In a large bowl combine oats, flour, sugar, baking powder, baking soda, cinnamon and nutmeg.
In a smaller bowl beat egg throughly, then add oil and vanilla. Add mixture to wet ingredients. The dry ingredient may not become completely incorporated with the wet ingredients at this point.
În a small bowl mash the bananas. Add the bananas to the rest of the ingredients and stir until combined.
Using a cookie scoop divide muffin batter into muffin tins or silicon cups; filling until nearly full.
Combine sugar and cinnamon and sprinkle evenly over muffins
Bake for 20 minutes or until a toothpick comes out clean.