Heat a griddle over medium-low heat. Mix together dry ingredients. Beat eggs into 1 1/2 cups milk, then stir in melted, cooled butter if using. Stir mixture into dry ingredients, mixing only to moisten flour; don't worry about lumps. If thick, add more milk.

Place a teaspoon or 2 of butter or oil on griddle. When butter foams or oil shimmers, ladle batter onto griddle, making pancakes of any size. Adjust heat as needed; the first batch generally requires higher heat. Flip pancakes after bubbles rise and bottoms brown, about 2 to 4 minutes.

Cook until second side is lightly browned. Serve, or hold in a 200-degree oven for up to 15 minutes.