Mix the butter. In a large mixing bowl with a hand mixer, or a stand mixer with the whisk attachment, whisk the softened vegan butter on medium speed for 3 minutes. It should be smooth and creamy. If it starts to curdle, it has been over mixed.
Add and whisk. Add the vanilla, salt, and half of the powdered sugar. Start on low speed and slowly build up speed until the sugar is incorporated. Add the remaining sugar, again mixing on low until it’s incorporated. Mix on medium to high speed for 2 to 3 minutes until light and fluffy. Add plant based milk as needed to get the right consistency.
Frost and enjoy! Transfer to a piping bag or use a spoon to frost cakes, cupcakes, cookies, and more! Enjoy!