Growing up in the Midwest and attending a Big 10 university, I associate Buckeyes with Ohio State and not with a combination of chocolate and peanut butter. Peanut butter and chocolate is always a winning combination. I remember the Reese's PB Cup commercials that just showed someone dipping a chocolate bar into a jar of peanut butter. This is a little more subtle than that...but not much.
From the Eagle Brand Classic Recipes book:
1 (18.25 oz) package chocolate cake mix (used devil's food)
1/4 cup vegetable oil
1 cup chopped peanuts
1 (14oz) can sweetened condensed milk (used fat-free)
1/2 cup peanut butter
Preheat oven to 350. In a large bowl combine cake mix, oil and egg and beat until crumbly. Stir in peanuts. Save 1 1/2 cups of the crumb mix and press the remaining in the bottom of a greased 13x9 baking pan.
Beat sweetened condensed milk with peanut butter until smooth. Pour over prepared crust. Sprinkle remaining crumb mixture on top. Bake 25-30 minutes until set. Cool and cut into bars (again - small for easy guilt-free sharing).