In a large mixing bowl, mash the ripe banana with a fork until almost smooth.
Add the egg whites, Greek yogurt, buttermilk, and vanilla extract to the bowl, whisking until the wet ingredients are well combined.
Sift in the oat flour, vanilla protein powder, baking powder, cinnamon, and sea salt.
Gently fold the dry ingredients into the wet mixture until just combined, being careful not to overmix the batter.
Preheat a large non-stick griddle or skillet over medium-low heat and lightly coat with avocado oil or cooking spray.
Ladle approximately 1/4 cup of batter per pancake onto the hot surface.
Cook for 3-4 minutes until bubbles begin to form on the surface and the edges look set.
Carefully flip the pancakes and cook for an additional 2 minutes until they are golden brown and cooked through.
Plate the pancakes and drizzle with pure maple syrup before serving warm.