Line a rimmed baking sheet with parchment or a silpat. Place the chopped peanuts (or mini chocolate chips, or coconut, if using) in a wide, shallow dish. Set aside.

Use a potato masher to mash the banana and peanut butter together until well-incorporated. Fold in the wheat germ, and form tablespoon-sized scoops of the mixture into balls. Roll the balls in the chopped peanuts, pressing gently, to coat, and arrange on the parchment-lined baking sheet as you go. Refrigerate for 25-30 minutes, until firm.

Store refrigerated in a covered container for up to one week.