Chocolate & Peanut Butter Chip Bars

If you need a quick, crowd-pleasing dessert that’s easy to make in bulk, these Chocolate & Peanut Butter Chip Bars are a top contender. Adapted from the King Arthur Cookie Companion, this recipe was originally called “Ruth Wakefield Chocolate Chip Cookie Bars” in honor of the inventor of the chocolate chip cookie.

No Mixer Required

These chewy cookie bars are rich, buttery, and packed with chips—perfect for bake sales, potlucks, or sharing with friends. The best part? You don’t need a mixer. Just grab two bowls, a whisk, and your favorite combination of chips. I like to use a mix of dark chocolate and peanut butter chips for a sweet-and-salty twist. But there's room for improvisation! Customize the bars with whatever you have on hand.

These bars bake up with a shiny, crackly top and soft centers, just like the best brownies—but with the classic flavor of a chocolate chip cookie and a hint of peanut butter from the chips. Interestingly, the original KA recipe does not call for vanilla. I add it anyway.

Baking Notes

• Flour Amount -- Please go by weight if possible. Some of King Arthur's old recipes use very light cups of flour. For instance, this one originally called for 2 ¾ cups of flour and a weight of 320 grams. I've changed it to 2 ½ cups volume, but the weight should still be 320 grams. I'm not sure how King Arthur got 320 grams for 2 ¾ cups, but flour's density can vary.
• Chip Combinations: I used a 50/50 blend of dark chocolate chips and peanut butter chips. You can use all chocolate, all peanut butter, or even swirl in some white chocolate chips for contrast.
• Add Nuts: For more texture, try folding in ½ cup of chopped pecans or walnuts or add ⅔ cup shredded unsweetened or sweetened coconut.
• Pan Size: The recipe makes a generous 15x10 inch pan batch. For thicker bars, you can bake them in a slightly smaller pan and adjust the bake time.
• Storage: These bars keep well at room temperature for several days and freeze beautifully, making them a great make-ahead option for events or gifting.

Adapted from the King Arthur Cookie Companion.

• Chocolate Peanut Butter Everything Cookies
• Double Chocolate Peanut Butter Cup Cookies
• One Bowl Peanut Butter Milk Chocolate Cookies
• Chewy Chocolate Peanut Bars
• Peanut Butter Bar Cookies

Recipe

Chocolate & Peanut Butter Chip Bars

Anna

A good bar cookie for bake sales and group events, adapted from King Arthur Flour's Ruth Wakefield's Chocolate Chip Cookie Bars, but with peanut butter chips. There's no peanut butter in the dough, so if you'd like to skip the peanut butter theme, just use a different flavor of chocolate chips.

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Prep Time 10 minutes mins

Cook Time 25 minutes mins

Cooling Time 30 minutes mins

Total Time 35 minutes mins

Course Dessert

Cuisine American

Servings 36 bars

Ingredients

 

• 2 ½ cups unbleached all-purpose flour (weigh out 320 grams for best results) (320 grams)
• 2 ½ teaspoons baking powder
• ½ teaspoon salt
• ⅔ cup unsalted butter
• 2 ½ cups light brown sugar (very tightly packed) (504 grams)
• 3 large eggs
• 1 teaspoon vanilla extract (optional)
• 1 cup chocolate chips (milk or semisweet)
• 1 cup peanut butter chips
• 1 cup chopped walnuts or peanuts
• ½ cup M&Ms mini baking bits (optional)

Instructions

 

• Preheat the oven to 350 degrees F. Spray 10x15 inch jelly roll pan with baking spray. For thicker bars, you may use a 9x13 inch pan and bake for about 30 minutes (possibly slightly longer).
• Mix the flour, baking powder and salt together and set aside.
• In another large bowl, combine the hot melted butter and brown sugar, stirring until smooth. Allow the mixture to cool slightly. Add the eggs one at a time, beating well after each addition. If using vanilla, add that too.
• Stir in the flour mixture. Make sure the mixture is cool, then add the chips and nuts. Spread the batter in the prepared pan. If using M&Ms you can add them with the other chips or sprinkle them on top.
• Bake the bars for 24 to 26 minutes, until their top is shiny and golden. Don’t overbake (I slightly underbaked mine) or the bars will be dry; a cake tester inserted into the center will not come out clean. Remove the bars from the oven and cool to room temperature before cutting. Note: If baking in a 9x13 inch pan, the bars will take about 30 to 35 minutes.

Notes

It's best to weigh the flour for these old King Arthur recipes., as their cups of flour tend to be light and fluffy.  For instance, this recipe calls for 2 ¾ cup of flour and a weight of 320 grams. That means each up of flour weighs 116 grams. I rarely if ever have a cup of flour that weighs 116 grams. The range is usually 125 to 140, so I've adjusted the volume amount to 2 ½ cups to equal 320.  For best results, just weigh out 320 grams.

Keyword Peanut Butter Bars

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