Preheat the oven to 350 degrees and grease a 12 muffin tray with oil and set aside. In a large mixing bowl, combine the coconut flour, oat flour, baking powder, baking soda, cinnamon, granulated sweetener and protein powder and mix well. In a small bowl, whisk together the egg whites and vanilla extract and add it to the dry mixture. Add the dairy free milk, 1/4 cup at a time, until a thick batter is formed. Pour the batter into the greased muffin tray until 3/4 of the way full and bake in the oven for 12-15 minutes, or until the tops come out golden and a toothpick comes out clean from the centre. Allow the muffins to cool completely before topping with the glaze. Prepare your cinnamon bun glaze by whisking all ingredients in a small bowl.