Whisk together 2 cups of all-purpose flour, 1 cup of granulated sugar, 2 teaspoons of baking powder, 1/2 teaspoon of salt, and 1 teaspoon of ground cinnamon until well combined.

In a separate bowl, mix together 1 cup of milk, 2 large eggs, 1/4 cup of melted butter, and 1 teaspoon of vanilla extract until smooth.

Gently pour the wet mixture into the dry ingredients and fold together using a spatula. Stir until just combined.

Add 1 cup of peeled, cored, and diced apples to the batter, folding them in gently.

Preheat the waffle iron according to the manufacturer's instructions and lightly grease the plates with vegetable oil.

Spoon a generous amount of batter onto the preheated waffle iron and cook for about 4 to 5 minutes until golden brown.

Once cooked, lift the waffle donuts from the iron and transfer them to a wire rack to cool slightly.

Using a donut cutter, cut out donut shapes from your waffle squares.

Heat vegetable oil in a heavy pot to 350°F (175°C).

Carefully lower the donut shapes into the hot oil and fry for about 2-3 minutes on each side until golden brown.

Remove and drain the donut shapes on a paper towel-lined plate.

In a small bowl, whisk together 1 cup of powdered sugar and about 2-3 tablespoons of milk until smooth.

Dip the cooled donuts into the glaze and set aside to let the glaze set.