1cupdark chocolate chips(or milk or semi-sweet chocolate)
¾cuppeanut butter chips
14ouncessweetened condensed milk
Preheat the oven to 350 degrees. Line a 9x13-inch baking dish with parchment paper allowing it to hang over on two sides, like a sling. (Note 2)
In a large mixing bowl, combine the cake mix, peanut butter, eggs, and ½ cup melted butter. Stir until the dough comes together. Press ⅔ the dough into the prepared pan. (Save the remaining dough to use as the topping.) Set aside.
In a small saucepan, combine the chocolate and peanut butter chips, sweetened condensed milk, and 2 tablespoons of butter. Melt over low heat, stirring constantly, until melted and combined. Spread this mixture over the dough in the pan. Using your fingers, arrange pieces of the remaining dough over the top of the filling.
Bake for 20-25 minutes until light golden brown. Cool completely before cutting into squares. Store in an airtight container.
Do not use reduced-fat peanut butter. The consistency will not be the same.
Spray the pan with cooking spray before lining it with parchment paper. This will hold the parchment in place, making it easier to spread the dough in the pan.
After cooling the bars to room temperature, chill them for another 15-20 minutes. This makes it easier to lift them from the pan and neatly slice them.