01 - Set oven to 350°F. Line a 12-cup muffin tin with paper liners or lightly coat with nonstick spray.
02 - In a large mixing bowl, whisk together pumpkin puree, mashed banana, eggs, vegetable oil, milk, and vanilla extract until smooth and cohesive.
03 - In a separate bowl, thoroughly blend all-purpose flour, granulated sugar, brown sugar, baking soda, baking powder, salt, cinnamon, nutmeg, and ginger.
04 - Gradually add the dry mixture into the wet mixture, stirring just until combined. Avoid overmixing for optimal texture.
05 - If desired, gently fold in chopped nuts or chocolate chips to the batter.
06 - Spoon batter evenly into the prepared muffin tin, filling each cup approximately three-quarters full.
07 - Bake in the preheated oven for 20 to 22 minutes, or until a toothpick inserted into the center emerges clean.
08 - Allow muffins to rest in the pan for 5 minutes, then transfer to a wire rack to cool fully before serving.