In a medium bowl, combine the flour, sugar, baking powder, and cinnamon.

In a large bowl, whisk the egg. Add the bananas and use a fork to mash it well. Once mashed, combine it with the whisked egg and try to eliminate as many lumps as possible. Add the milk, melted butter, and vanilla and mix to combine.

Add the dry flour mixture into the large wet ingredients bowl and mix until just combined. A few banana lumps are normal. If you want to eliminate any remaining lumps, use a fork to press them into the bowl to avoid overmixing the batter

Heat a large non-stick pan or griddle over medium-high heat. Once hot, spray or grease with butter or oil and immediately pour about ¼ cup of batter per pancake.

Cook the first side for about 2 minutes until the edges are defined and bubbles form in the middle. Flip and continue cooking on the other side for another minute. Don't press the pancakes down after flipping.

Remove from the griddle or pan onto a plate and repeat the process with the remaining pancake batter. Keep them warm in the oven in the lowest setting, covered with a clean kitchen towel, or covered with a plate.

Serve them warm topped with sliced bananas and syrup.