In a large mixing bowl, whisk together the all-purpose flour, baking powder, salt, and white sugar until well combined.
In a separate bowl, beat the egg, then add melted butter and milk. Mix until smooth.
Create a well in the center of the dry ingredients and then pour the wet ingredients in and stir until just combined. Do not overmix; it's okay if the batter is slightly lumpy.
Lightly grease the skillet or griddle with butter or cooking spray.
Then pour about ¼ cup of batter onto the skillet for each pancake. Cook for 1-2 minutes until bubbles form on the surface and the edges look set, then flip and cook the other side until golden brown.
Repeat with the remaining batter, adjusting the heat as needed to prevent burning.
Serve the pancakes warm with your favorite toppings.