Start by gathering all of your ingredients. Make sure your bananas are ripe for the best flavor and sweetness. Separate the egg whites from the yolks in two different mixing bowls.
In the bowl with the egg yolks, add the Greek yogurt, mashed bananas, almond milk, dark brown sugar, salt, and vanilla extract. Whisk together until smooth and well combined.
In a separate bowl, mix the oat flour, whole wheat flour, and baking powder. Stir to combine the dry ingredients thoroughly.
Using a whisk or an electric mixer, beat the egg whites until they form soft peaks. This will add airiness to your pancakes.
Gently fold the dry ingredients into the wet mixture until just combined. Be careful not to overmix; a few lumps are fine. Then, fold in the beaten egg whites until no streaks remain. If using, add the chocolate chunks now.
Heat a skillet or griddle over medium heat and add a tablespoon of butter. Allow it to melt and coat the surface.
Using a 1/4 cup measuring cup, pour the batter onto the skillet. Cook until bubbles form on the surface, about 2-3 minutes, then flip and cook for another 2-3 minutes until golden brown. Repeat with the remaining batter, adding more butter to the pan as needed.
Serve the pancakes warm with a drizzle of maple syrup. They are delightful on their own or paired with fresh fruit, nuts, or additional chocolate chunks!