Ingredients
Topping
1/2 cup light brown sugar
1/2 cup all-purpose flour
1/4 cup creamy peanut butter
2 tablespoons unsalted butter, melted
1 cup semisweet chocolate chips (I used a combination of milk chocolate and semisweet)
Cake
2 cups all-purpose flour
2 teaspoons baking powder
1/2 teaspoon baking soda
1/2 teaspoon salt
1/2 cup creamy peanut butter
1/4 cup (1/2 stick) unsalted butter, at room temperature
1 cup light brown sugar
2 large eggs, at room temperature
1 cup milk, at room temperature
Preparation
Preheat oven to 375 F. Spray a 13x9 baking pan with cooking spray.
To make the topping: Stir the brown sugar and flour together in a medium bowl, breaking up any lumps of brown sugar. Add the peanut butter and melted butter, stirring until the mixture is crumbly. Mix in the chocolate chips then set aside.
To make the cake: Whisk the flour, baking powder, baking soda and salt together in a medium bowl. In the bowl of a stand mixer fitted with the paddle attachment, beat the peanut butter and butter on medium speed until creamy and smooth. Add the brown sugar and continue beating on medium until the mixture is light and fluffy. Add the eggs, one at a time, beating well after each addition. With the mixer on low alternately add the dry ingredients and milk, beginning and ending with the flour mixture, and beating just until combined.
Spread the batter evenly in the prepared pan. Sprinkle the topping evenly over the cake. Bake for 30-35 minutes, or until the cake is golden brown and a toothpick inserted in the center comes out clean. Transfer the pan to a wire rack and cool for at least 30 minutes before slicing and serving.
