Add the butter and cream cheese to a large bowl. Beat the mixture with an electric mixer until evenly combined, about 2 minutes.
Add the salt and sweetener, one tablespoon at a time, and continue to beat until pale and fluffy (8-10 minutes). Feel free to scrape the bowl as needed, and adjust sweetness to taste. Add vanilla extract and beat until fully incorporated.
If making a chocolate version, sift the cocoa in one tablespoon at a time and beat until fully incorporated.
One batch of frosting is enough for roughly 12 cupcakes.
Notes
You can pretty much use whatever sweetener floats your boat. But it must be powdered. Xylitol (non-corn though to avoid tummy troubles!) and allulose are my top choice (no aftertaste!), and Lakanto (slight cooling, but barely any aftertaste!).So get your blender out, make sure it’s completely dry, and process your sweetener of choice until powdered. Just make sure you wait a few moments for the dust to settle before opening the blender or food processor.Or you can always grab a bag of Powdered Lakanto (just keep in mind its twice as sweet…. or even go for pure monkfruit extract (love Lakanto’s!) or stevia!