In a large bowl mix together the flour, sugar, baking powder and salt.
Add the egg, milk, vanilla, oil and bananas; stir until thoroughly combined (batter may be slightly lumpy).
Melt the butter on a non stick griddle over medium heat.
Pour 1/4 cup sized pancakes onto the griddle. Cook until bubbles cover surface, 2 to 3 minutes. Flip, and cook until bottom is golden, about 1-2 minutes more.
Serve immediately and top with maple syrup and banana slices if desired.
Make Ahead: Sometimes when I make pancakes or waffles I mix up an extra batch of the dry ingredients and keep it in a labeled bag. That way, the next time I want to make pancakes all I have to do is add the wet ingredients and I'm done.