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Home » All-Time Favorites

Marshmallow Krispie Topped Brownies

Modified: Mar 15, 2025 · Published: Jan 10, 2008 by Anna · This post may contain affiliate links · 51 Comments

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I first made Marshmallow Krispie Topped Brownies back in 2008 and had no idea how popular they'd become with my friends. For a bake sale, event or party, these are a sure thing. The recipe starts with packaged brownie mix, so it's almost foolproof.

marshmallow krispie topped brownies with packaged brownie mix

Thanks to the brownie mix, these come together quickly. Packaged brownie mix works really well here because it's not too rich and doesn't upstage the peanut buttery-chocolate crispy topping. Peanut Butter Marshmallow Krispie Topped Brownies have everything going for them -- the texture, flavor, easiness.  They will always be one of our favorites.

Packaged Brownie Mix Box Sizes

Since posting the recipe I've experimented with different size boxes of packaged brownie mix and it doesn't seem to matter which size or brand you use since you just use the directions and ingredients called for on the box for the base. 

Marshmallow Krispie Topped Brownies in an 8 Inch Pan

The recipe below is designed for a 13x9 inch pan of brownies, but you can also make them in an 8 inch pan by halving everything.  Some brownies mixes are designed for 8 inch pans, so you could also use one of those mixes and just halve the toppings.

Storing Marshmallow Krispies Topped Brownies

To bake a day ahead, just bake, let cool, cover and refrigerate until the next day. For longer term storage, freeze the brownies. Prepare as directed and let cool. Lift from pan and cut the pan of brownies into two big squares. Wrap in plastic, then put each square in a large freezer bag. Store in the freezer until ready to serve. After you pull them from the freezer, you can slice them while partially frozen.

  • Caramel Krispie Bars
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Recipe

Easy Peanut Butter Marshmallow Krispie Topped Brownies

Anna
Easy Peanut Butter Marshmallow Krispie Topped Brownies
5 from 11 votes
Print Recipe Pin Recipe
Prep Time 10 minutes mins
Cook Time 2 hours hrs
Total Time 2 hours hrs 10 minutes mins
Course Dessert
Cuisine American
Servings 24

Ingredients
 

  • 1 box 18.3 to 21 oz brownie mix plus eggs & oil (or whatever box calls for)
  • 4 cups marshmallows small ones
  • 1 ⅓ cup semi-sweet chocolate chips
  • 1 cup creamy peanut butter – regular type
  • 3 tablespoons butter
  • 2 cups crispy rice cereal

Instructions
 

  • Preheat oven to temperature directed on brownie package.
  • Line a 13x9 inch pan with non-stick foil.
  • Prepare brownies using amount of oil, eggs, water called for on box. Two minutes before they are supposed to be done, pull brownies from the oven and sprinkle marshmallows across top. Return to oven for 2 minutes to soften marshmallows. Remove from oven and spread soft marshmallows over top of brownies. Let cool completely on a wire rack.
  • Prepare topping. In a microwave-safe bowl, combine chocolate chips, peanut butter and butter. Heat on high for 30 seconds. Stir and repeat until chocolate is melted and mixture is smooth. Add cereal and stir to coat. Drop spoonfuls of chocolate mixture over marshmallow layer, spreading as evenly as possible. Things will look gooey at this point, so don’t even think about cutting. Put the brownies in the refrigerator for a few hours to chill.
  • Lift from pan and score into squares (about 16 or 20).
  • Half Batch Version
  • This recipe halves well. Just cut everything in half (half a 19.5 oz box of brownie mix is 2 cups mix) and bake in a non-stick foil lined 8 inch square metal pan. Bake time will be about 22 minutes total.

Notes

Cook time includes time needed to cool and chill
Tried this recipe?Let us know how it was!

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Comments

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  1. Anna says

    August 12, 2024 at 7:51 am

    Mine too!

  2. e-ticaret sitesi says

    August 12, 2024 at 7:02 am

    5 stars
    These are one of my favorites.

  3. Anna says

    November 26, 2023 at 12:49 pm

    Thanks for the review!

  4. Christine says

    November 26, 2023 at 12:47 pm

    5 stars
    Made these last year around Xmas and my MIL requested them again this year. Definitely a hit and now will be in the rotation!

  5. Anna says

    April 28, 2018 at 9:02 am

    These are one of my favorites.

  6. Sue says

    April 28, 2018 at 7:55 am

    5 stars
    I made these for a housewarming party and they turned out great. I’ve made a different version in the past but your recipe was easier for me to find and I have no regrets about going with this version. I was worried that the Rice Krispie part was too fluid but it thickened up nicely.

  7. Jodi Mravlja says

    April 24, 2012 at 1:00 pm

    5 stars
    These are so simply to make and so very delicious. I made them for a bakesale and they were gone within minutes.

  8. Elsie Paroz says

    March 04, 2012 at 2:17 pm

    5 stars
    If you are a real chocoholic, make this recipe by substituting Cocoa Crispies!!!! Also, can use 7 oz. jar of marshmallow cream, taking lid off and heating in microwave for 1 min. or so and spreading over top of COOLED brownies then put choc. peanut butter, Cocoa Crispie mixture on top!~!! VERY GOOD!!!!!

  9. Lorraine says

    February 24, 2012 at 11:37 am

    5 stars
    These looked sooo good, I had to go get krispie cereal and mini-marshmallows to bake them up yesterday! They are delicious and a nice gourmet looking brownie! And sooo easy to make!

  10. Sara says

    May 06, 2011 at 9:46 pm

    5 stars
    These came out great, my brownie layer was a little thinner than I would have liked (my box of mix was 17.5 ounces or something and designed for an 8x8 pan) but the combination of the textures was great. I topped them with a sprinkle of the mini PB cups from Trader Joes 🙂 Thanks for the guidance on storing them!

  11. corinne says

    April 13, 2011 at 11:38 am

    The movers came yesterday and took nearly all our kitchen stuff, but I need to make a dessert for my roommates' last dinner tonight...this looks doable! Not having even a whisk, never mind a mixer, has put most of my bookmarked recipes out of reach...

  12. Sarah says

    March 15, 2011 at 7:29 pm

    5 stars
    I never had better brownies. I liked how the brownie condensed and the krispie topping plus the brownie made a regular thickness brownie. The crunch is such a bonus!

  13. Anna says

    March 12, 2011 at 6:43 pm

    Becky, thanks for the review! This is one of my all-time favorite recipes (at least right now), so I'm always happy to hear from people who like it as much as I do. My favorite thing about this one is all the different textures.

  14. Becky says

    March 12, 2011 at 5:33 pm

    5 stars
    I just made these and they are outrageously good! My boys voted them the best cookie they've ever eaten, which is saying something since I cook/bake a lot and we are big foodies!

  15. pumpkinpie says

    December 15, 2010 at 6:25 am

    5 stars
    Yum! My husband calls these 'fudgy buddies', because the topping is like muddy buddies. Bet they would be good with some pretzels...

  16. kara says

    December 05, 2010 at 2:48 pm

    One of my favorite recipes is a variation of these!Rather than using marshmallows, you use chopped Reese's pb cups and also peanuts if you want a little more crunch. We call them "Better Than Crack Brownies." Soooo delicious!

  17. Anna says

    June 05, 2010 at 1:08 pm

    Marita, I hope you like them!

  18. Marita says

    June 05, 2010 at 1:02 pm

    THANK YOU!!!!!!!!!!! My mother's best friend (she was like a Mom to me after my mother passed when I was 11) used to make these everytime we went to her house because I loved them so much. My mother is gone and her friend now has Alzheimer's. I have wanted to make these for so long.

  19. anon says

    February 11, 2010 at 6:35 pm

    I can't wait to try these!!! They look absolutely delicious!

  20. d says

    February 10, 2010 at 10:59 pm

    However did I miss these the first time around??? I love all your "Favorites Lists" . Thanks for all your efforts. I have made so many fun recipes from this blog. You're making me popular!!!

  21. Richard Walker says

    January 29, 2010 at 9:08 pm

    My kids love this thanks.............

  22. ashley says

    August 31, 2009 at 3:22 pm

    all i can say is........AMAZING!!!!!!!

  23. Louise says

    June 12, 2009 at 1:43 pm

    These are cooling right now. They are for the "Women in the Outdoors" event at our gun club tomorrow. Maybe they won't eat them and I'll get to bring them home. 🙂

  24. Anna says

    September 21, 2008 at 3:32 pm

    Hi Mimi,

    I do think it would work. Let me know how it goes! Maybe you could do a half batch for experimentation.

  25. Mimi says

    September 21, 2008 at 2:19 pm

    Hey Anna, I was wondering if it would be possible to omit the peanut butter and just use milk chocolate to melt with the rice krispies...do you think it will stay together nicely?

  26. Anna says

    July 29, 2008 at 8:10 pm

    Kelsey, I'm glad you had a chance to try them. I think this is one of my favorite bar cookies in the world. If I didn't feel the need to try something new all the time, I would make these over and over again.

  27. Kelsey the cook says

    July 29, 2008 at 8:03 pm

    5 stars
    These were absolutely delicious! My friends loved them! I even made them in a miniature cupcake way! The kids loved them! Thanks!

  28. Shabneez says

    April 30, 2008 at 6:22 pm

    I made these the other day and they were awesome! (Although how can you go wrong with brownies, peanut butter, and Rice Krispie treats?)

    I didn't want to use a brownie mix, so I subbed the Baker's One Bowl Brownie recipe. Not much more difficult, and the resulting brownies worked well with the marshmallow and Rice Krispie topping.

    Thanks for the recipe! 🙂

  29. karen says

    March 17, 2008 at 5:08 pm

    I tried these at a church youth rally and now that I have the recipe I will be making them for my quilt guild meeting this week! Forget halving the recipe, I know I will have to double (or even triple!) the recipe because the family will not let me out of the house without leaving some for them too! They are so good, two favorites, chocolate and peanut butter!
    Thanks

  30. Debbi says

    January 17, 2008 at 8:06 am

    I made these last week and they were very nummy. I think that I used a bit too much marshmallow but they were still good. The kids loved them!!

  31. Vickie says

    January 14, 2008 at 6:58 pm

    Oh. My. Goodness. How good does that look?

    I am bookmarking this recipe (too) as I like to bake goodies and deliver them to friends, work cohorts and neighbors. This looks like it would be popular with both adults and kids.

    Thanks!

  32. Tina says

    January 12, 2008 at 12:52 pm

    Hello Anna!

    I just made these for church tomorrow and we all loved them here!! I hope that you're having a nice weekend so far.

  33. steph says

    January 12, 2008 at 10:58 am

    Hi Anna,
    With the smore brownie I found it extremely hard to cut and it didn't look very pretty. The marshmellow was just too gooey. This krispy topped brownie cut well and tasted sooo good.
    So far I have made these brownies, the macadamia nut with Bailey's Irish creme, Wellesy chocolate chips, pistashio white chocolate jumbles and your toffee. All fabulous. Thanks for the recipes but also your insights on meaurements and equiptment and that kinda stuff.
    Have a nice weekend!

  34. Anna says

    January 12, 2008 at 8:06 am

    Hi Steph,

    What happened with your S'Mores brownies? Was it the scratch part you had issues with or spreading the marshmallows? Maybe you commented and I just need to go back and check.

    Glad you liked this one! You know, you could probably do the S'mores brownies with mix. Just follow the Smores crush recipe, but bake the mix as directed above (or on the box) and pour it over the crust.

  35. steph says

    January 12, 2008 at 7:38 am

    These were just yummylicious! I had a box of Pillsbury brownies and they worked just fine. I was nervous because I didn't have much success with the smore brownie you posted over New Years but this was great. The rice krispy concoction "spread" nicely over the marshmellows and I did wait a couple of hours to cut them into bars. Altogether a keeper of a recipe!! Thanks!

  36. Katie says

    January 12, 2008 at 1:55 am

    Oh wow those look amazing and totally over indulgant! Never seen anything like these before, I intend to try soon.

  37. Anna says

    January 11, 2008 at 4:30 pm

    Wanda, thanks for the photo compliment. I'm dying to make something else today just so I can photograph it and post it.

    Jessica, I think the marshmallow layer helps keep these from tasting excessively rich. The top is kind of like a peanut butter flavored crunch bar or something.

  38. Jessica says

    January 11, 2008 at 3:54 pm

    What a great variation on the brownie! I never thought of topping a brownie with a Rice Krispie Treat (peanut butter, no less). But hey, excess is excellent.

  39. Wanda says

    January 11, 2008 at 2:46 pm

    Oh boy. These are great. They are really very easy to make and so yummy. Completely blew the diet. Excellent photo Anna.

    Wanda
    http://www.only-cookware.com

  40. Anna says

    January 11, 2008 at 1:21 pm

    I finally had a whole one and Wow! These are SO good. The half batch version worked out beautifully and I had just enough to share. But I'll definitely be making a full batch of these for a bake sale or something.

  41. Katie says

    January 11, 2008 at 1:17 pm

    WOW, these look incredible. And easy! I can't wait to try these.

  42. Christy says

    January 11, 2008 at 8:31 am

    I had forgotten about these goodies. A woman at our church used to bring these to our fellowships. If you wanted one, you would have to grab it early.

  43. Emiline says

    January 10, 2008 at 9:51 pm

    Oh, I forgot to tell you welcome back from Disney World. Welcome back!

    Ok, now to the bars. These look perfect. That picture could be in a magazine.

  44. e says

    January 10, 2008 at 9:26 pm

    Excellent. I love the peanut butter and marshmallow combination. FlufferNutters were a favorite of mine as a kid. I can't wait to make these.

  45. Anna says

    January 10, 2008 at 9:09 pm

    Thanks Anj,

    I don't know what I'm enjoying more now -- baking or taking the pictures. I'm having so much fun with my new camera and light box.

  46. Anna says

    January 10, 2008 at 9:08 pm

    Cakespy, I gave a bunch to my friend Rachel (Average Jane Crafter) but the rest are still here, waiting to be eaten. I meant to save these for tomorrow, but couldn't help myself and had a few tastes. I love Rice Krispie Treats, but these are way more interesting.

    Therese, I can't believe it's taken me this long to try this recipe. It's an old one recipe but I never see it anywhere. I think I'll make it for the next school function....or bake sale. These slice really well and aren't the least bit gooey if you chill them long enough.

    Oh, and the protein! Yes! That and the fact that Rice Krispies are fortified qualifies these as a highly nutritious snack ;).

  47. Anj says

    January 10, 2008 at 9:03 pm

    Those look wonderful. Your new camera takes beautiful pictures!

  48. Therese says

    January 10, 2008 at 8:43 pm

    ANNA!

    I have this recipe!! These are sooooooooo good!
    I like to keep them in the fridge...I like when the chocolate sets and they way they taste. Whenever I make these the recipe is always requested. I wish my thighs didn't like them as much as I do. Good protein with the peanut butter though...right??!!! tee hee!!
    I have made them with various brownie mixes...the chocolate chunk is good with this too!!
    It is good to see you in the cooking groove...that is the Anna we love!!!

  49. Cakespy says

    January 10, 2008 at 8:24 pm

    These look great, a nice and little bit more interesting take on the rice krispie treat. I bet they're already gone!

  50. Anna says

    January 10, 2008 at 6:59 pm

    Well, you can be the first to review since I gave most of them to your husband :).

  51. Average Jane Crafter says

    January 10, 2008 at 6:41 pm

    These look YUMMY!!!!

Peanut Butter Fudge Jumbles recipe baked in a 9-inch square Pampered Chef stoneware pan.

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I'm Anna, and welcome to Cookie Madness. To learn more about me, check the About page.

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