In a mixing, whisk together flour, cocoa powder, sugar, baking powder, baking soda and salt.
In another mixing bowl, combine mashed banana, egg (or egg replacer mixture), vanilla extract and oil.
Pour wet ingredients into dry ingredients and mix until just combined. Do not overmix. Set aside for 10~15 minutes.
Heat a griddle on medium flame, pour ¼cup of batter and cook till bubbles form on the top, about 1~2 minutes. Gently flip and cook for another 1~2 minutes. Serve right away or keep them warm in a 200°F oven until ready to serve.