In a large bowl, whisk together the flour, sugar, baking powder, and salt.
Add the milk, egg, vanilla, and melted butter. Stir gently until just combined. A few lumps are fine.
If the batter seems too thick, add a little more milk until it reaches a pourable consistency.
Heat a lightly greased skillet or griddle over medium heat.
Pour about ¼ cup of batter onto the hot skillet for each pancake.
Cook until bubbles form on top and the edges begin to set, about 2 to 3 minutes.
Flip and cook another 1 to 2 minutes, until golden brown and cooked through.
Serve warm with butter, syrup, or your favorite toppings.