If it's not already softened, remove the cream cheese from its packaging, cut it into cubes, and place them in a microwave-safe bowl. Microwave in 10-second bursts until soft but still holding its shape, not melted.
Place the softened cream cheese in a bowl and add the stevia and vanilla.
Beat until smooth, about 2 minutes with a whisk or 1 minute with an electric mixer, scraping down the sides of the bowl.
Spread the frosting on cupcakes or cakes or transfer it to a piping bag and pipe it on.