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 well combined.
04 - Stir the grated carrots into the wet ingredients until evenly distributed.
05 - Add the wet mixture to the dry ingredients and mix gently until just combined. Do not overmix to maintain texture.
06 - Fold in the chopped walnuts, if using, until evenly distributed throughout the batter.
07 - Pour the batter into the prepared loaf pan and spread evenly with a spatula.
08 - Bake for 50-60 minutes, or until a toothpick inserted in the center comes out clean.
09 - Let the bread cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.