Let cake refrigerate for at least 4 hours before serving, so the frosting has a chance to set.
*To make the prepared aquafaba, simply drain a can of chickpeas (best to use no salt added). Place the aquafaba in a small saucepan. Bring it to a boil over medium high heat, reduce heat, let mixture simmer for about 10 minutes, or until it reduces until about half. So you will need 2/3 cup of aquafaba to make this recipe. I always like to actually make more, just in case I let it boil past the point of reducing to half and end up with too little aquafaba. Let it cool down before using it. I typically like to refrigerate it first, because it adopts a thicker consistency. And then let it come to room temperature for 10 minutes before using in my recipe.