Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan and set aside.
In a large bowl, whisk together the flour, baking powder, salt, cinnamon, nutmeg, granulated sugar, and brown sugar until well combined.
In another bowl, beat the eggs, then add the milk, melted butter, and vanilla extract. Mix until smooth.
Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix.
Gently fold in the diced apples and nuts (if using) until evenly distributed.
Pour the batter into the prepared loaf pan and spread it evenly.
Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean.
While the bread is baking, prepare the glaze by whisking together the powdered sugar and milk until smooth.
Once the bread is done, allow it to cool in the pan for about 10 minutes before transferring it to a wire rack. Drizzle the glaze over the warm bread.
Let the bread cool completely before slicing.