Preheat oven to 350°F. Spray a 9″ x 13″ baking dish with cooking spray, then line with a sheet of parchment paper. Lightly spray top of paper.

Combine cake mix, peanut butter, canola oil and the egg in a mixing bowl or stand mixer.

Press the mixture together on the parchment in the dish, forming an even layer on the bottom of the baking dish.

Top the crust with peanut butter chips, chocolate chips and peanut butter cup minis, and peanuts {optional}. Pour sweetened condensed milk over everything.

Bake at 350°F for about 25-35 minutes.

Let cool completely in dish. Lift baked dough out of dish by holding edges of parchment paper. Cut into bars or squares. The size of the cut bars will determine how many this will make, but they are very rich, so opt for a smaller