Prepare the dry ingredients by whisking together all-purpose flour, granulated sugar, baking powder, cinnamon, nutmeg, and salt in a mixing bowl.

Combine the wet ingredients by whisking together milk, large egg, melted butter, and vanilla extract in another bowl until smooth and creamy.

Mix the batter by gently pouring the wet ingredients into the dry ingredients and stirring until just combined, aiming for a slightly thick batter.

Fold in the diced, peeled apples carefully to ensure they are evenly distributed.

Preheat your waffle iron to medium-high heat and lightly grease it with cooking spray or oil.

Cook the waffle donuts by spooning the batter into the preheated waffle iron and cooking for 3 to 4 minutes until golden brown.

Make the glaze by whisking together powdered sugar, milk, and vanilla extract until smooth.

Drizzle the glaze over warm waffle donuts, letting it soak in for a tasty finish.