This is a recipe by Ernst Knam which can be used in plenty of creations and it's also gluten free.
Equipment
Stand mixer (optional)
Ingredients
2 Egg yolks
10g Powder sugar (1)
2 Egg whites
67g Powder sugar (2)
30g Cocoa powder
10g Potato starch
Process
Whisk the egg whites and when all bubble disappeared add the powder sugar. Keep whisking until firm peaks.
Whisk the egg yolks with powder sugar (by hand is fine) and mix it gently with the egg whites using a spatula.
Add the cocoa powder and the potato starch and mix with spatula until fully incorporated.
Put on a baking tin on baking paper to have 2-3 cm thickness. Bake for around 9-10 mins at 200°C degrees.
When taking out from the oven put some granulated sugar on top and let it rest.