Prepare Caramelized Apples: In a skillet over medium heat, melt 2 tablespoons of butter. Add 1 cup of diced apples, 2 tablespoons of brown sugar, and 1 teaspoon of ground cinnamon. Cook for about 5-7 minutes, stirring occasionally, until the apples are tender and caramelized.

Mix Dry Ingredients: In a large mixing bowl, combine 1 ½ cups of all-purpose flour, ½ cup of granulated sugar, 2 teaspoons of baking powder, ½ teaspoon of baking soda, 1 teaspoon of cinnamon, and a pinch of salt. Whisk until well blended.

Mix Wet Ingredients: In a separate bowl, whisk together ¾ cup of buttermilk, 1 large egg, 4 tablespoons of melted butter, and 1 teaspoon of vanilla extract until smooth.

Combine Mixtures: Pour the wet ingredients into the dry mixture, stirring gently to combine. Fold in the caramelized apple mixture. Let the batter rest for a few minutes.

Cook Waffle Donuts: Preheat your waffle iron and lightly grease it. Spoon about ½ cup of the batter onto the hot iron and close the lid. Cook for approximately 3-4 minutes, or until golden brown.

Make Glaze: In a medium bowl, whisk together 1 cup of powdered sugar, 2-4 tablespoons of milk, and a splash of vanilla extract to achieve a smooth consistency.

Glaze Donuts: While donuts are warm, dip the tops into the glaze or drizzle it generously over them. Let the glaze set before serving.