Combine egg whites, honey and sugar in mixing bowl placed over double boiler. Whisk constantly over low-medium heat until honey and sugar are fully dissoved and mixture is very warm to the touch. (approximately 150 degrees)
Remove from heat, fit mixer with whisk attachment and whisk until bowl is cool, mixture is fluffy and stiff peaks form. This can take 8-15 minutes, be patient!
Add the butter in tablesppon increments and beat until combined. Switch to paddle attachment and beat until fluffy. Add vanilla an beat until combined.
Notes
If you’re looking for the perfect fluffy buttercream, look no further! This Swiss meringue buttercream is a nice alternative to powdered sugar frostings because it’s not ridiculously sweet, plus it’s so creamy and pipes perfectly too.