1 (18.25 ounce) package brownie mix (such as Pillsbury(R))
2/3 cup vegetable oil
1/4 cup water
2 cups confectioners’ sugar
1 cup creamy peanut butter
1/2 cup butter, softened
1 (6 ounce) package chocolate chips
6 tablespoons butter, softened
Preheat oven to 350 degrees F (175 degrees C). Grease a 9×13-inch baking dish.
Combine brownie mix, oil, eggs, and water together in a bowl until batter is smooth; pour into the prepared baking dish.
Bake in the preheated oven until edges of brownies begin to pull away from the sides of pan, 28 to 31 minutes. Remove dish from oven and cool brownies.
Beat confectioners’ sugar, peanut butter, and 1/2 cup butter together in a bowl until smooth and creamy; spread over cooled brownies.
Heat chocolate chips and 6 tablespoons butter together in a saucepan over low heat, stirring occasionally, until melted, about 5 minutes; spread over peanut butter layer. Cool and cut into squares.