This is a double batch of my favorite vanilla buttercream! It's great for larger cakes, small 2-tiered cakes, or cakes with a lot of frosting decorations (buttercream rosettes, buttercream ruffles, etc.)
Beat the butter on a medium speed for 30 seconds with a paddle attachment, until smooth. Slowly add in the powdered sugar, 1 cup at a time. Alternate with small splashes of cream.
Once fully mixed, add in the vanilla and salt, and beat on low until the ingredients are fully incorporated, and the desired consistency is reached.
If the frosting is too thick, add in additional cream (1 teaspoon at a time). If the frosting is too thin, add in more powdered sugar (quarter of a cup at a time).
If you are making frosting for a cake, it is important to mix the buttercream on low at the end of the process for a couple minutes, to get out any extra air that might have be incorporated during the mixing process. This will make it easier to get super smooth sides on your cake!