In a large bowl, sift together the flour, baking powder, salt, and sugar. Whisk to combine evenly.
In a separate medium bowl, whisk together the buttermilk and the egg until well combined.
Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix; a few lumps are perfectly fine.
Gently fold in the melted butter until just incorporated.
Heat a lightly oiled griddle or frying pan over medium-high heat. Pour or scoop the batter onto the griddle, using approximately ¼ cup for each pancake. Brown on both sides and serve hot.