In a high-speed blender, combine the egg whites, Greek yogurt, oat flour, half of the banana, cinnamon, baking powder, sea salt, and vanilla extract.
Blend on high until the batter is completely smooth and creamy, then let the mixture sit for 2 minutes to allow the oats to hydrate.
Slice the remaining half of the banana into thin, even rounds for the topping.
Heat a large non-stick skillet over medium heat and lightly coat the surface with half of the coconut oil.
Pour the batter into the skillet to form three or four medium-sized pancakes, leaving space between them.
Cook for 3-4 minutes until bubbles form on the surface and the edges look set, then flip and cook for another 2 minutes until golden brown.
Remove the pancakes from the skillet and set them aside on a warm plate.
In the same skillet, add the remaining coconut oil, maple syrup, and the banana slices.
Sauté the bananas for 1-2 minutes per side over medium heat until they are soft and the syrup has thickened into a golden glaze.
Stack the pancakes high on a plate and top with the caramelized banana slices and any extra syrup remaining in the pan.