Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line it with parchment paper.

In a large mixing bowl, combine the mashed bananas, grated carrots, granulated sugar, brown sugar, vegetable oil, eggs, and vanilla extract. Mix well until fully combined.

In a separate bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, and nutmeg.

Gradually add the dry ingredients to the wet ingredients, stirring until just combined. Be careful not to overmix.

If using, fold in the chopped nuts and raisins or dried cranberries.

Pour the batter into the prepared loaf pan and smooth the top with a spatula.

Bake in the preheated oven for 50-60 minutes, or until a toothpick inserted into the center comes out clean.

Allow the bread to cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.