Preheat oven to 375 degrees.
Line a muffin pan with paper cups, or use nonstick spray.

1. In a large bowl, stir together the banana and peanut butter.
   
   
2. Add the remaining ingredients and mix together until well combined. (You may want to use your hands.)
   
   
3. Spoon the batter into the prepared muffin pan, filling the cups to the top.
   
   
4. Bake for 20 minutes or until the tops are slightly brown and muffins are firm.
   
   
5. Cool in the pan for 5 minutes, then remove the muffins and place on a wire rack to cool completely.
   
   
6. Store the baked muffins, tightly covered, at room temperature for up to 4 days.