Using a hand held mixer or standing mixer, cream the butter using a paddle or whisk attachment on medium high until pale yellow, about 4-5 minutes. If necessary, half way through scrape down the sides of the bowl and continue mixing.
Turn off the mixer and add powdered sugar and salt. Mix on low for a minute until it incorporates and starts to look crumbly.
Once crumbly, turn up the speed and continue mixing on medium to medium high, about 3-4 minutes until light and fluffy.
Add the champagne and vanilla. Mix until combined. Gauge frosting consistency, you can add another 1-2 tablespoons of champagne if a thinner frosting is desired. This frosting has a mild champagne flavor- see post for getting a stronger champagne flavor.
Add to your favorite dessert and enjoy!
Notes
Make sure you like the type of champagne or sparkling wine you use. If you don’t like it, you might not like the flavor of the frosting.
Mix the butter for a good 3-4 minutes before and after adding the powdered sugar. Mixing the frosting for so long makes for a very light and fluffy buttercream, and helps cut the graininess of the powdered sugar.
This frosting has a mild champagne flavor, see the post for how to give it a stronger flavor.
This recipe makes about 3 cups of frosting and can easily be halved or doubled.
This recipe will last up to two weeks in the fridge or up to two months in the freezer.