Add the bananas to a large mixing bowl and mash with a fork until few chunks remain.
Add the egg yolks, buttermilk, coconut oil, maple syrup, and vanilla to the bananas. Mix until combined.
Add the flour, baking powder, baking soda, salt, and the optional cinnamon to a separate mixing bowl and stir until combined.
Add the dry ingredients to the wet ingredients and mix until thoroughly combined.
Add the egg whites to the batter and stir until just combined. Set aside to rest for 5 minutes.
Preheat a griddle or skillet over medium heat. Add the batter by ⅓ cup scoops. Cook the pancakes on one side for 3 to 4 minutes until they start to bubble on the surface. Flip and cook another 2 to 3 minutes.