In a large bowl, mix buttermilk, egg, vanilla extract, and melted butter until smooth. Pour the dry ingredients into the wet ingredients and stir gently until just combined; a few lumps are okay.
Heat a nonstick skillet over medium heat and lightly brush with melted butter. Pour about 1/4 cup of batter per pancake onto the skillet.
Cook the pancakes for 2-3 minutes until bubbles form on the surface and the edges look set, then flip and cook for another 1-3 minutes until golden brown.