01 - Preheat the waffle iron according to manufacturer's instructions.
02 - In a large mixing bowl, whisk together oat flour, vanilla protein powder, ground cinnamon, baking powder, and salt.
03 - In a separate mixing bowl, whisk eggs, almond milk, melted coconut oil, maple syrup, and vanilla extract until well blended.
04 - Pour the wet ingredients into the bowl with dry ingredients. Stir gently until just combined, ensuring not to overmix.
05 - Gently fold in the diced apple to evenly distribute throughout the batter.
06 - Lightly coat the heated waffle iron with cooking spray or a small amount of oil.
07 - Spoon about 1/2 to 3/4 cup of batter onto the waffle iron (amount varies by model). Close and cook until the waffles are golden brown and crisp, approximately 3 to 5 minutes.
08 - Continue with remaining batter, reheating and greasing the waffle iron as needed.
09 - Serve the waffles warm, with optional toppings such as extra apple slices, ground cinnamon, or a drizzle of maple syrup.