Using an electric mixer, beat the butter on high for 30 seconds until it becomes fluffy. Add the confectioners/icing sugar a 1/2 cup at a time. Beat for 1 minute more. Add the freeze-dried powder and beat more.
Frost your cake and serve. Your frosting will be smooth and ready to spread. We recommend doing so just ahead of serving.
Depending on the season and humidity, the buttercream will not keep long at room temperature and will harden in the refrigerator, so live in the moment. Frosting takes a minute.
You can prepare buttercream ahead. It will keep refrigerated for up to a week.
The idea for preparing a vegan buttercream came about after an obsession with this cake from Daily Bread. That and I was still thinking about The Caker Matcha Cherry Cake that we ate for Goji's third birthday. So when we were looking for a cake for our holiday celebrations, this was where we landed. I purchased the Lemon Strawberry Poppy Seed Cake Kit and bought a Naturli Organic Vegan Block, and on the 24th, we made buttercream—the American version, which is what this is, and it is also the simplest. I'd do it again in a heartbeat. Now I will look for anything relatively celebratory as an excuse to prepare this buttercream. For guidance, I have included further explanation below.
I would also recommend this video on Facebook for The Caker technique when frosting a cake.
Use room-temperature ingredients — If you are to make the buttercream of your dreams, room-temperature ingredients will incorporate better with less chance of separation and ensure the smoothest consistency.
Do not microwave your butter — Butter that is too soft is more likely to cause separation or develop a curdled appearance that no amount of beating will correct. Your butter should be soft enough you can easily break off pieces but not so soft it smears.
How long will your buttercream keep? — You can prepare yours ahead and refrigerate it for up to a week. Store buttercream in an airtight container—otherwise, it might absorb flavours within your fridge. When you are ready to use your buttercream, remove from the refrigerator an hour ahead to return the buttercream to room temperature. Beat with an electric mixer for a minute or so until the buttercream has regained its whipped creamy texture.
Buttercream flavour variations — Make it your own by adding vanilla bean, mint essential oil or any other ingredient that speaks to you. For matcha, the amount depends on how green and grassy you want the flavour to be but I would recommend starting with 1 teaspoon and add more as required. A little goes a long way! For vanilla, use 1 to 2 teaspoons of pure vanilla extract with a quarter teaspoon of fine Himalayan Sea Salt.
