Core and dice the apple into small, uniform cubes.
Heat a small non-stick skillet over medium heat and add the ghee.
Add the diced apples and a pinch of the cinnamon to the skillet, sautéing until they are tender and fragrant.
Drizzle the maple syrup over the apples to glaze them, then remove the skillet from the heat and set aside.
In a high-speed blender, combine the egg whites, Greek yogurt, oat flour, baking powder, sea salt, vanilla extract, and the remaining cinnamon.
Blend on high for 30 seconds until the batter is completely smooth and slightly aerated.
Pre-heat a large non-stick griddle or skillet over medium-low heat.
Pour the batter onto the griddle to form three medium-sized pancakes, leaving space between them.
Cook for 3 to 4 minutes until bubbles appear on the surface and the edges look set, then flip and cook for another 2 minutes until golden.
Transfer the pancakes to a plate and spoon the warm caramelized apples over the top before serving.