Preheat your oven to 400°F and line or spray your muffin tin.
Peel your bananas and add them to a large mixing bowl. Use a fork to mash the banana, until completely broken down.
2 large overripe bananas
Add your pumpkin puree, butter, vanilla extract, and both sugars to the bowl with your mashed bananas. Use a whisk or hand mixer to combine until mostly smooth (a couple of larger pieces of banana is okay!).
15 ounces pumpkin puree, ½ cup softened unsalted butter, 1 teaspoon vanilla extract, ½ cup granulated sugar, ½ cup light brown sugar
Add flour, baking soda, salt, and pumpkin pie spice and again use your whisk or hand mixer to combine until there are no lumps of powder present.
2 cups all-purpose flour, 1 teaspoon baking soda, 1 teaspoon salt, 2 teaspoons pumpkin pie spice
Lastly, add the milk and whisk to combine to thin out your batter until it's smooth (again, some banana chunks are okay!).
½ cup milk
Fill your muffin cups with batter, almost all the way to the top, leaving only about 1/2-inch of space.
Add crumble topping (optional, recipe below) and bake for 30-35 minutes until toothpick comes out clean.