Prepare cupcakes as directed on Pillsbury Devil’s Food Cake box.
Bake regular or miniature size cupcake and allow to cool.
Prepare peanut butter filling by beating peanut butter, butter, and confectioners sugar together on Low until combined and then on High speed until thoroughly combined.
Put peanut butter filling in a large freezer bag, cutting a small piece at the bottom of one corner.
Core a hole out of the cooled cupcakes using a Cupcake Corer.
Squeeze peanut butter filling into cupcakes, leaving a smooth edge on top to create the Buckeye Candy look.