Set oven to 350F.
Mix together all of the dry ingredients in a bowl.
In a separate bowl, mash up the cooked potato. Note: if the cooked potato has been in the fridge, allow it to settle to room temperature to make it easier to manage. Add in a ripe banana and mash with a fork.
Add the remaining wet ingredients to the bowl with the potato and mix together using a hand mixer (recommended).
Fold in the dry ingredients and mix everything together. If desired, add the chocolate chips OR your favorite frozen berry.
Spray a mini-muffin pan with nonstick cooking/baking spray.
Evenly divide the batter among the molds (I put 1 chocolate chunk on top of each one).
Bake for 25 minutes until golden brown, or until a toothpick comes out clean whenever the muffin is pierced.
Allow to cool for a brief moment in the molds, then enjoy!
Store in the refrigerator or freezer in a sealable bag or container.