8tablespoonssalted butter, softened, plus extra for pan( 114 grams)
¾cuplight brown sugar, packed(150 grams)
1largeegg, room temperature
1teaspoonpure vanilla extract
¾cupmilk chocolate chips
¼cupwhite chips or mini white chips
Optional
½cupmarshmallows
Instructions
Preheat the oven to 325 degrees F. Line an 8-inch square metal pan with foil or parchment paper. Grease pan with extra salted butter for extra flavor! Or feel free to use cooking spray.
Combine the flour, malt powder, baking soda and salt, Stir until evenly mixed and set aside.
Beat the butter and brown sugar until creamy. By hand or using lowest speed of your mixer, stir in the egg and vanilla.
Stir flour mixture into butter mixture. When flour is almost fully blended in, add chocolate and white chips and mix until flour disappears. For super chewy bars, you can stir in some marshmallows. They are completely optional.
Scrape batter into pan and spread evenly.
Bake for about 30 minutes or until they are browned on top and pull away from the edges. The center should be a tiny bit jiggly, but will set as the bars cool. Note: I've overbaked them (3 minutes), and while they were very brown, they still tasted good. It's a little tricky to figure out exactly when they are done because the malted milk powder causes them to brown more.
Transfer to a wire rack and let cool. Grasp foil, lift from pan and cut into bars.
You can serve them at room temperature of chill.
Notes
If you accidentally overbake bar cookies, you can sometimes save them by lifting from the pan, setting them on a small tray (with the foil or parchment underneath) and immediately putting them in the freezer.