Preheat Oven: Set your oven to 350°F (175°C). Grease and flour a 9x5 inch loaf pan.
Prepare Ingredients: In a small bowl, toss the blueberries with a tablespoon of flour to coat (this prevents them from sinking during baking). Set aside.
Mix Wet Ingredients: In a large bowl, mash the bananas. Add sugar, oil, and the egg. Beat until well combined.
Combine Dry Ingredients: In another bowl, sift together flour, baking powder, baking soda, salt, cinnamon, and nutmeg.
Combine Wet and Dry Ingredients: Gradually stir the dry ingredients into the wet ingredients, mixing just until combined.
Add Blueberries: Fold in the flour-coated blueberries gently to distribute evenly.
Bake: Pour the batter into the prepared loaf pan. Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean.
Cool: Allow the bread to cool in the pan for 10 minutes, then turn out onto a wire rack to cool completely.