Here is a link to the recipe I used: http://nami-nami.blogspot.com/2009/01/egg-white-cake-recipe-angel-cake-recipe.html.
But in case you don't want to convert the European measurements, I'll write out the conversions here.
6 large egg whites
1 c + 2 Tbsp. caster sugar
1 Tbsp. cornstarch
1 tsp. baking powder
1 1/4 c. flour
7 Tbsp. melted butter, slightly cooled
Bake at 350 F.
This cake is good even without frosting. It's very dense and kind of spongy.