Line a muffin tin with liners or grease and set aside.
Combine the flour, baking soda, baking powder, salt, and spices (cinnamon, nutmeg, cloves, and ginger) Whisk.
Combine the mashed bananas, pumpkin puree, sugar, oil, eggs, and vanilla in the bowl of a stand mixer or a large mixing bowl. Beat well until well blended.
Slowly stir in the dry ingredients mixture until just combined. Don’t overmix.
Divide the batter evenly between the prepared muffin wrappers - filling each about ¾ full.
Combine the cinnamon/sugar topping ingredients in a small bowl and then divide that mixture evenly on the tops of the muffin batter.
Bake for 20-25 minutes or until the toothpick test returns clean but with a few moist crumbs.
Cool the muffins in the tin for 5-10 minutes before transferring to a wire rack to cool at room temperature.
Notes
Tips Be sure to measure your flour using the proper spoon and level method. Don’t scoop out of a compacted bag of flour. This can result in far too much being added and a dry, dense muffin.
Be sure to use very ripe bananas for the right amount of sweetness. If the pumpkin puree is too watery, strain it out before using. You want to use thick puree.
Don’t try to store the muffins before they have cooled completely or they will get soggy.
To freeze - wrap each muffin individually in plastic wrap, then place them in a large zip-top bag. Thaw in the refrigerator. Microwave for 20 seconds.
Store in an airtight container at room temperature for up to 3 days. Place a paper towel at the bottom of the container and on top of the muffins to absorb excess moisture. OR store them in the refrigerator for up to a week.