01 - Preheat oven to 350°F. Line a muffin tin with paper liners or grease lightly.
02 - In a large bowl, whisk together the pumpkin puree, mashed banana, eggs, oil, milk, and vanilla extract until homogeneous and smooth.
03 - In a separate bowl, combine the all-purpose flour, granulated sugar, brown sugar, baking soda, baking powder, salt, cinnamon, nutmeg, and ginger; mix just until evenly distributed.
04 - Add the dry ingredients to the wet ingredients and gently mix just until incorporated. Avoid overmixing to ensure a tender crumb.
05 - If desired, fold in the chopped nuts or chocolate chips with a spatula.
06 - Divide the batter evenly into the prepared muffin tin, filling each cup approximately three-quarters full.
07 - Bake for 20 to 22 minutes, until a toothpick inserted in the center emerges clean.
08 - Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely before serving.