Melt the butter by heating over a double boiler or in the microwave. Beat the egg and set aside.
Add the cake flour, baking powder, and sugar to a bowl and mix in a circular motion.
Add the egg and milk a little at a time and mix well. Once it's smooth, add the butter.
Add one ladle's worth of the batter (about 80 ml) to your waffle maker and cook.
Story Behind this Recipe
These are American waffles that you can easily make using only one egg. Addition: they're more light and soft than heavy and springy.
In step 3, if you don't add the milk slowly while mixing, it'll clump up. If you mix the egg and milk at the beginning and set aside, it makes things easier. When cooking, if you feel like it's not cooking well try turning it over and cooking a bit more.