If you don’t want to use egg white, you can use already pasteurized eggs or aquafaba. Aquafaba is the thick liquid in a can of chickpeas that you usually drain out and throw away. It is commonly used in vegan baking as a substitute for egg whites and whips up just as well as egg whites in this recipe.
This recipe works best with fine, granulated sugar. But it also works with many other sugars. Make sure the egg white/aquafaba is stiff before adding the sugar, especially if using a heavy sugar like coconut sugar.
Do not add the cocoa powder until instructed or the egg whites will not properly whip. The powder will weigh the mixture down too much to froth properly.