01 - Preheat the oven to 350°F. Grease and flour a 9x5-inch loaf pan or line with parchment paper.
02 - In a large bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, nutmeg, and ginger until well blended.
03 - In a separate bowl, beat the eggs, then add mashed bananas, oil, brown sugar, granulated sugar, and vanilla extract. Mix until thoroughly combined.
04 - Stir the grated carrots into the wet ingredient mixture until evenly distributed.
05 - Add the wet mixture to the dry ingredients and fold gently until just combined. Avoid overmixing to prevent dense texture.
06 - Gently fold in the chopped walnuts if using, distributing evenly throughout the batter.
07 - Transfer the batter to the prepared loaf pan and spread evenly with a spatula.
08 - Bake for 50–60 minutes, or until a toothpick inserted in the center emerges clean.
09 - Allow the bread to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.