Preheat oven to 350 degrees F and line a muffin tins with liners.
In a medium-sized bowl, mash the bananas. Stir in the shredded carrots.
Add the melted butter, sugars, egg and milk to the banana mixture and whisk until combined. Set aside.
In another medium-sized bowl, whisk together the baking powder, cinnamon, baking soda, salt, nutmeg, flours and oats. Then pour the wet banana mixture into the flour mixture and gently mix with a spatula just until combined.
Use a portion scoop to fill the muffin liners about ¾ of the way. Sprinkle with a few oats on top of each muffin (optional)
Bake on the upper baking rack for 18-20 minutes for standard muffins, until lightly golden.
Remove from the oven, and let them cool in the pan for 5 minutes and then transfer to a cooling rack until fully cooled.
