In a large mixing bowl, whisk together the sifted flour, baking powder, salt, and sugar until well combined.
Add the warm milk to the dry ingredients, stirring gently to begin forming the batter.
Whisk in the beaten egg, blending until the mixture is smooth and slightly frothy.
Pour in the melted butter and stir until just combined; do not overmix, as this can make the pancakes dense.
Let the batter rest for a few minutes; it will thicken slightly and become more uniform.
Heat a non-stick skillet or griddle over medium heat until hot; you can test this by flicking a few drops of water—the water should dance and evaporate quickly.
Lightly grease the skillet with a small amount of butter or cooking spray, then pour 1/4 cup of batter for each pancake.
Cook the pancakes for 2-3 minutes, until bubbles form on the surface and the edges look set; gently flip with a spatula.
Cook for another 2-3 minutes on the second side until golden brown and cooked through.
Transfer the cooked pancakes to a plate, stacking them as you go, and keep warm while you cook the remaining batter.
Serve the pancakes warm with your favorite toppings like syrup, fresh fruit, or whipped cream, and enjoy!