First separate the eggs. Beat the egg whites until stiff and set aside.
Then beat the egg yolks until frothy. Stir in the mashed banana, margarine and possibly a lemon zest. Mix the flour with the baking powder and the milk alternately into the dough. Finally fold in the egg white.
Bake the dough in a waffle iron in portions until golden brown.
The batter makes about 10 waffles, depending on the waffle iron.