Line muffin pan with muffin papers and pre-heat oven to 350 degrees.
In a large mixing bowl put peeled ripe bananas, pumpkin, and sugars. Mash together.
Stir in vegetable oil, eggs, and vanilla.
Stir in baking soda, flour, and spices.
Using a tablespoon, fill muffin papers 3/4 full with muffin batter. Sprinkle crumble top on top of each muffin before baking. (See below for crumble top instructions).
Bake at 350 degrees for 15-17 minutes. Remove from oven and cool.
Enjoy!
For the Crumble Top:
Melt butter. Stir in brown sugar, flour, and oatmeal.
Crumble top will be like a thick dough. Take a handful and "crumble" it over the muffin batter.