In a large bowl, whisk together the flour, sugar, baking powder, and salt.
In another bowl, combine the milk, egg, melted butter, and vanilla extract.
Pour the wet ingredients into the dry ingredients and gently mix until just combined.
Preheat a non-stick skillet or griddle over medium heat.
Lightly grease the skillet with butter or oil.
Pour 1/4 cup of batter onto the skillet for each pancake.
Cook until bubbles form on the surface, about 2-3 minutes.
Flip the pancakes and cook until golden brown, about 2 more minutes.
Remove from the skillet and keep warm in a low oven.
Repeat with remaining batter, greasing the skillet as needed.