Separate eggs. Beat yolks in a medium bowl with sugar and salt. Add milk and flour alternately, stirring by hand gently after each addition, to form a thin, smooth batter. Stir in melted butter. (Batter can be covered and refrigerated at this point for up to a day.)
Beat egg whites until shiny and glossy and they hold stiff peaks. Gently fold them into batter; do not worry about fully incorporating them.
Heat a cast iron, heavy skillet or griddle over medium-high heat; when a drop of water skips across it before evaporating, it’s ready.
Melt some butter in pan (don’t be shy with it) and using a tablespoon, scoop up a bit of batter and put it in pan. Cook as many pancakes at once as will fit comfortably, turning them when they are brown.
Cook the pancakes quickly over fairly high heat. Total cooking time is less than 3 – 4 minutes per pancake.
Serve with powdered sugar, preserves or jelly, sour or whipping cream. Have syrup at the ready; someone will inevitably want some.