If you need to soften your cream cheese, remove it from the wrap, cube it, and place it in a microwave-safe bowl. Microwave in 10-second sessions, until soft but not liquid.
Add the vanilla and stevia.
Using a hand whisk, whisk vigorously, until the frosting is completely smooth and fluffy, about 2 minutes.
If you prefer to use an electric whisk, start whisking on low speed until the mixture is uniform, then increase the speed to medium and beat until fluffy, about 1 minute, scraping the sides of the bowl with a rubber spatula as needed.
Spoon the frosting on top of six cupcakes and spread to frost the top, or use a piping bag. You can also use this frosting to frost a single-layer cake.
The amounts listed here make enough frosting for six cupcakes or for a one-layer cake. For 12 cupcakes or for a two-layer cake, double the amount.