Beat butter and peanut butter in a medium mixing bowl with electric mixer. Gradually mix in the sugar.

When it starts to thicken, add milk one tablespoon at a time until sugar is well mixed and frosting is a spreadable consistency.

Beat for about three minutes to make it fluffy.

After cake has cooled completely, crumble the cake into small pieces in a large mixing bowl.

Mix in the peanut butter frosting about a half cup at a time. Fully incorporate each half-cup full and try to roll out a 1.5 inch ball in the palm of your hand. The consistency should be neither too sticky nor too dry.

Roll the cake mixture into bite-sized balls and place on baking sheet covered in waxed paper.

Set the pan in freezer for about half an hour for the balls to "set".

(If you are using lollipop sticks, melt the chocolate bars according to microwave directions, and dip each stick slightly into the chocolate and then into the cake balls before freezing.)

Melt the chocolate in the microwave or according to the package directions. Be sure you use a deep bowl (rather than wide and shallow) because you will be "dipping" the balls into the chocolate.

Reheating as needed to keep it as liquid as possible.

If you did not use sticks, get a couple forks to use for dipping.

Line the balls again on the waxed paper surface to harden.