01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners or grease lightly with cooking spray.
02 - In a large bowl, whisk together mashed bananas, pumpkin puree, eggs, melted butter, brown sugar, maple syrup, and vanilla extract until thoroughly combined and smooth.
03 - In a separate medium bowl, stir together flour, baking soda, baking powder, salt, cinnamon, nutmeg, ginger, and cloves until evenly distributed.
04 - Add dry ingredients to wet mixture. Gently fold with a spatula until just combined—do not overmix as this will result in dense muffins.
05 - Fold in walnuts, pecans, and/or chocolate chips if desired.
06 - Evenly divide batter among muffin cups, filling each about 3/4 full.
07 - Bake for 20–22 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs.
08 - Let muffins cool in pan for 5 minutes, then transfer to a wire rack to cool completely.