In a large bowl, whisk together the flour, sugar, baking powder, baking soda, and salt. Create a well in the center of the dry ingredients.
Pour the milk, cooled melted butter, vanilla extract, and egg into the well. Begin by whisking the wet ingredients in the center, gradually incorporating the dry ingredients until just combined. Do not overmix. If your batter is too thick, add milk, one tablespoon at a time, until pourable.
Let the batter rest for about 5 minutes.
Preheat a nonstick pan or griddle over low-medium heat. Lightly grease with a small amount of butter or coconut oil.