Step 1

As needed, reduce your aquafaba to get a slightly slimy consistency. In a small saucepan, simmer the aquafaba on low heat until it has reduced by a third to a half. If your aquafaba is thick straight from the can, feel free to skip this step.

Step 2

In a saucepan, mix the aquafaba and sugar together and bring to a boil over medium heat. Transfer the aquafaba into a container and let the preparation cool down until it is at room temperature. This is also a great time to get your vegan butter out of the fridge to let it come up to room temperature.

Step 3

In the bowl of a stand mixer, add the aquafaba, cream of tartar, and xanthan gum. Using the whisk, whip up the aquafaba on high until you reach stiff peaks. This will take between 7 and 10 minutes.

Step 4

Slowly add the vanilla and the butter, cube by cube, waiting between each addition that the previous cube is almost completely incorporated before adding the next one.

Step 5

Whip the vegan swiss meringue buttercream for 10 minutes, or until it is light in color and has a subtle butter taste. Optional: As needed, swipe a blowtorch on the outside of the bowl of your stand mixer (if it is made of metal) for 20 to 30 seconds at a time, keeping the flame moving constantly if you have trouble incorporating the butter. This should be gentle heat and the butter should not melt.

Step 6

Change the whisk for the paddle attachment and whip the swiss meringue buttercream on low for 2 to 3 minutes to remove any air bubbles. You can also press the buttercream against the side of the bowl with the help of a silicone spatula to get rid of any large air bubbles.

Step 7

Color and use as needed, or refrigerate in an airtight container for up to 1 week. Enjoy!