Using a stand (or hand) mixer fitted with the paddle attachment, beat butter on medium-low speed until smooth and creamy, 1 minute.
Turn the mixer off and add the powdered sugar, 2 tablespoons of cream, vanilla, almond, and salt. Begin mixing on low speed until the ingredients come together - scraping the bowl occasionally.
Turn up the speed and mix at medium-high speed for 3 to 5 minutes, until the buttercream is light, airy, and nearly white. If needed, add the additional cream until desired consistency is achieved. The buttercream should spread smoothly without tearing the crumb of the cake but thick enough that it holds shape when piped and spread between the layers.
If using to ice a smooth cake, vigorously stir with a wooden spoon or stiff spatula to knock out some of the air bubbles.
Notes
Almond buttercream frosting is best used just after making while it is still soft. If making in advance, store it at room temperature for up to 1 day. Rewhip or mix by hand until light and smooth.Frosting may be stored in the refrigerator for up to two weeks. Allow it to come to room temperature before remixing. You may also freeze the frosting for up to 3 months. Thaw in the refrigerator overnight.