Beat egg with hand beater until floppy, beat in remaining ingredients just until smooth. For thinner pancakes, stir in additional ¼ cup milk. Grease heated griddle if necessary. (To test griddle, sprinkle with few drops water. If bubbles skitter around, heat is just right.
For each pancake, pour about 3 Tbsp butter from tip of large spoon or from pitcher onto hot griddle. Cook pancakes until puffed and dry around edges. Turn and cook other sides until golden brown. 9 4-inc pancakes.