01 - Preheat oven to 350°F (175°C). Line a muffin tin with paper liners or lightly grease each cup.
02 - In a large mixing bowl, whisk together the pumpkin puree, mashed banana, eggs, vegetable oil, milk, and vanilla extract until the mixture is smooth and homogenized.
03 - In a separate bowl, stir together the all-purpose flour, granulated sugar, brown sugar, baking soda, baking powder, salt, ground cinnamon, nutmeg, and ground ginger until well blended.
04 - Gradually add the dry ingredients into the wet ingredients, stirring gently until just incorporated. Avoid overmixing to maintain a tender crumb.
05 - Gently fold in chopped walnuts or pecans and chocolate chips if using, ensuring even distribution.
06 - Divide the batter equally among the prepared muffin cups, filling each approximately three-quarters full for optimal rise.
07 - Bake in the preheated oven for 20 to 22 minutes or until a toothpick inserted in the center of a muffin emerges clean.
08 - Allow muffins to cool in the pan for 5 minutes before transferring them to a wire rack to cool fully.