Preheat your oven to 350°F (175°C). Line a muffin tin with paper liners or lightly grease each cup.

In a large bowl, mix the rolled oats, vanilla protein powder, unsweetened applesauce, and milk until well combined. Add the egg whites and melted coconut oil, stirring until smooth.

Fold in the coconut flour, granulated sweetener, baking powder, cinnamon, vanilla extract, and salt. Mix gently to avoid overmixing.

Create the cinnamon swirl by mixing granulated sweetener and additional cinnamon together.

Layer half of the muffin batter in the tin, add cinnamon mixture over it, then cover with remaining batter.

Bake for approximately 20 minutes until golden brown. A toothpick inserted should come out clean.

For optional glaze, blend cream cheese, powdered sweetener, milk, and vanilla until smooth.

Cool muffins in the tin for about 5 minutes, then transfer to a wire rack. Drizzle glaze over cooled muffins if desired.