Preheat oven to 350 degrees. Grease a 12-cup muffin pan.
In a bowl, combine flour, sugar, baking powder and salt, stirring with a whisk. Add cheese, stirring until covered with flour mixture. In a small bowl, combine milk and egg; stir into flour mixture until just blended. Stir in melted butter.
Fill prepared muffin pan with batter; bake 20 minutes.