Preheat your oven to 350°F (175°C) and grease a 9×5-inch loaf pan.

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

In another bowl, combine the sugars, oil, eggs, and vanilla extract using a mixer on medium speed until smooth and well-blended.

Gradually add the dry mixture into the wet ingredients until just combined. Be careful not to overmix.

Gently fold in the diced apples and nuts (if using) using a spatula.

Pour the batter into the prepared loaf pan and bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean.

While the bread is cooling, whisk together the powdered sugar, milk, and vanilla extract for the glaze.

Let the bread cool in the pan for about 10-15 minutes, then transfer it to a wire rack and drizzle the glaze on top.