In a mixing bowl, sift together flour, baking powder, salt and sugar.
In a second bowl combine milk, egg and melted butter.
Make a well in the center of dry ingredients and pour in wet. Mix until just combined.
Preheat a no peek square waffle maker on medium heat.
Using a measuring cup, pour 1 c. of batter into the hot waffle maker and close. The maker will indicate when the waffle is done.
Serve with warm maple syrup.