In a medium mixing bowl, combine the almond flour, protein powder, coconut flour, baking powder, and cinnamon.
Add the wet ingredients - the almond milk, eggs, and oil (if using) - to the bowl of mixed dry ingredients. Stir until well combined and smooth.
Add the grated apple, stir until evenly distributed throughout the protein pancake batter. Set aside.
Heat a large nonstick skillet over medium heat, spray with nonstick spray.
Use a ¼ cup measure to pour batter out into 3 small pancakes. (You can do all 6 at once, if using a larger surface, like my Cuisinart Griddler.)
Allow to cook until the underside is nicely golden brown, and small bubbles are breaking at the surface.
Carefully flip each pancake and cook for another 1-2 minutes, until golden brown on the second side, and JUST cooked through. Note: Overcooking can lead to dry pancakes!
If you only did the 3 pancakes to start, use the ¼ cup measure to pour the remaining batter into another 3 pancakes, repeat the cooking process.
Serve the apple cinnamon protein pancakes with your favorite toppings - butter, sugar free syrup, more berries, etc - or just plain.
Leftover pancakes can be stored in an airtight container in the fridge for a couple days.