Sift powdered sugar, salt, and cream of tartar. Set it aside.
Beat butter and vanilla for 5 minutes on medium speed until light and fluffy.
On low speed, slowly add powdered sugar alternating with whipping cream. Add more powdered sugar if needed, one tablespoon at a time. If the buttercream is too firm add one tablespoon of whipping cream at a time until you get the desired consistency.
Beat buttercream on medium speed until all ingredients are well combined.
Taste your buttercream and adjust flavors if needed.
Notes
If you need a white buttercream add one of two drops of purple coloring and use clear vanilla extract.
Feel free to use other flavors.
I recommend you use unsalted butter but if you are not able do not add the pinch of salt.
For a vegan buttercream use a vegan unsalted buttery spread and a vegan whipping cream.
Using coconut milk will work but keep in mind that it will alter the flavors.
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