In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt.
Whisk together buttermilk, egg, butter, and vanilla; pour over dry ingredients. Whisk until combined but still slightly lumpy.
Heat a large nonstick skillet or griddle over low-medium heat; lightly brush with some of the oil.
Pour batter, scant ¼ cup at a time, into the pan; spread slightly to form pancakes.
Cook until bubbles appear on top, about 3 minutes.
Flip and cook until bottoms are golden brown, about 1 minute.
Transfer to a rimmed baking sheet; cover and keep warm in a 250ºF (120ºC) oven.
