In a large mixing bowl, whisk together the sifted flour, baking powder, salt, and sugar until evenly combined. Visual cue: Dry ingredients appear uniformly distributed with no lumps.
1 1/2 cups all-purpose flour
In a separate bowl, whisk the milk and beaten egg together until smooth. Visual cue: Mixture is homogeneous with no streaks, looking slightly frothy on top.
1 1/2 cups all-purpose flour
Pour the wet ingredients into the dry ingredients, then add the melted butter. Gently fold everything together using a spatula until just combined. Visual cue: Batter is slightly lumpy but well incorporated, no visible streaks of flour or egg.
1 1/2 cups all-purpose flour
Preheat a griddle or non-stick skillet over medium heat until hot, about 2-3 minutes. Lightly grease with butter or oil. Visual cue: Surface glistens slightly and a drop of water sizzles upon contact.
Using a ladle or scoop, pour approximately 1/4 cup of batter onto the hot griddle for each pancake. Cook until bubbles form on the surface and edges look set, about 2-3 minutes. Visual cue: bubbles burst and edges turn golden brown; the underside is golden when carefully lifted with a spatula.
Flip the pancake using a spatula and cook for an additional 1-2 minutes, until the second side is golden brown and the pancake is cooked through. Visual cue: Both sides are evenly golden, and the pancake springs back when lightly pressed. Remove and keep warm before repeating with remaining batter.