Whisk the flour, sugar, baking powder, salt, and cinnamon in a large bowl.
In a separate bowl, whisk the milk, egg, melted butter, and vanilla.
Pour the wet ingredients into the dry and stir until just combined. Small lumps are fine.
Let the batter rest for 5 minutes.
Heat a lightly buttered skillet over medium-low heat.
Pour ¼ cup batter per pancake. Cook 2 to 3 minutes, until bubbles pop and the edges are set.
Flip and cook 1 to 2 minutes more, until golden.
Keep finished pancakes warm in a 200°F oven until serving.