01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners or grease lightly.
02 - Whisk together pumpkin puree, mashed banana, eggs, oil, milk, and vanilla extract in a large bowl until completely combined.
03 - In a separate bowl, blend flour, granulated sugar, brown sugar, baking soda, baking powder, salt, cinnamon, nutmeg, and ginger.
04 - Add dry ingredients to wet ingredient mixture and stir gently until combined; avoid overmixing.
05 - Fold in chopped walnuts or pecans and chocolate chips, if desired.
06 - Fill each muffin cup about three-quarters full with batter, dividing evenly.
07 - Bake 20 to 22 minutes, or until a toothpick inserted in the center emerges clean.
08 - Allow muffins to cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.