Peanut butter cookie layer:
- 1/2 cup plus 2 tablespoons all-purpose flour
- 1/4 teaspoon baking soda
- 1/4 teaspoon baking powder
- Pinch salt
- 1/2 stick (4 tablespoons) unsalted butter, at room temperature
- 1/4 cup granulated sugar
- 1/4 cup packed light brown sugar
- 1/4 cup peanut butter
- 1 large egg
Peanut butter cup layer:
- 16 chocolate peanut butter cups, such as Reese's
- 10 tablespoons (1 1/4 sticks) unsalted butter
- 1 cup granulated sugar
- 3/4 cup unsweetened cocoa powder
- 1/2 teaspoon salt
- 2 teaspoons vanilla extract
- 2 large eggs
- 1/2 cup all-purpose flour
For the peanut butter cookie layer:
In a medium bowl whisk together the flour, baking soda, baking powder, and salt.
In the bowl of an electric mixer beat the butter and sugars on medium speed until light and fluffy, 2-3 minutes. Beat in the peanut butter until combined. Beat in egg until combined. On low speed add the flour mixture, beating until just incorporated. Place in refrigerator until ready to use.
For the brownie layer:
Preheat oven to 350 degrees F. Line a 8x8-inch pan with tin foil then spray foil with non-stick cooking spray.
In a medium saucepan melt the butter. Remove from heat and add the sugar and cocoa powder, whisking to combine. Add salt, vanilla, and eggs. Whisk until combined. Add flour, mixing until just combined. Set aside.
Press cookie dough mixture into prepared pan, spreading evenly. Layer peanut butter cups in one even layer on top of cooking dough, pressing slightly. Pour brownie batter over peanut butter cups and cookie dough in one even layer. Bake for about 30 minutes, or until the edges are set. Don't overbake. Let cool completely before cutting into 16 bars. Brownies can be stored in airtight containers at room temperature for up to 3 days