Measure and sift the dry ingredients—flour, baking powder, salt, and sugar—into a large mixing bowl, ensuring even distribution.
Pour the milk into a separate bowl and add the lightly beaten egg; whisk briefly to combine.
Add the melted butter to the wet ingredients and stir until well incorporated, then pour this mixture into the dry ingredients.
Gently stir the batter with a spoon or spatula just until combined; a few lumps are okay—do not overmix, as this can deflate the batter.
Preheat the griddle or skillet over medium heat until hot, about 350°F (175°C). Lightly grease with butter or spray pan with cooking spray.
Pour 1/4 cup of batter onto the hot skillet for each pancake. Cook until small bubbles appear on the surface and the edges look set, approximately 2-3 minutes.
Flip the pancakes using a spatula and cook for an additional 2-3 minutes until golden brown on both sides and cooked through.
Remove the pancakes from the skillet and place on a plate. Serve warm with your favorite toppings.