Begin by preheating your waffle iron according to the manufacturer's instructions, lightly greasing it with cooking spray or melted butter.

In a large mixing bowl, combine all-purpose flour, baking powder, baking soda, salt, ground cinnamon, and nutmeg. Whisk these together until well blended.

In a separate bowl, whisk together the large eggs, granulated sugar, light brown sugar, buttermilk, melted butter, and vanilla extract until smooth and homogenous.

Gently fold the wet ingredients into the dry mixture, stirring until just combined. Fold in the diced tart apples and chopped nuts, if using.

Pour ¼ cup of batter into the center of the preheated waffle iron, closing the lid firmly. Let the waffles cook for about 3 to 5 minutes, or until they turn golden brown.

Once cooked, carefully transfer the waffles to a wire rack to cool slightly for about 1-2 minutes before glazing.

In a small bowl, whisk together the powdered sugar, milk, and vanilla extract until smooth and creamy.

Drizzle the glaze over the warm waffles, using a spoon to create a beautiful pattern. Dust with additional powdered sugar if desired.