In a glass bowl, whisk the egg whites and sugar, using an electric hand mixer, until thick and glossy.
In a separate bowl, combine the egg yolks, flour, baking powder, milk and butter. Whisk until there are no lumps. Fold through the egg whites until combined.
Using a non-stick frypan, brush the base with butter and heat over a low heat. Add 1/4 cup of pancake batter at a time and cook for 3 minutes, or until pancake bubbles completely. Flip pancake and cook for a further 3 minutes. Repeat until all pancakes are cooked.
In a saucepan, simmer the lemon, sugar, mint and water for 6 minutes or until thick. Pour over pancakes and serve.