Prepare the cupcake batter according to the package instructions. Divide the batter evenly among the prepared wells and bake until the cupcakes just spring back when lightly touched, about 25 minutes.
Transfer the pan to a wire rack and let cool for 10 minutes. Then transfer the cupcakes to the rack and let cool completely. If desired, use a serrated knife to level off the domed part of each cupcake before frosting.
Meanwhile, make the cream cheese frosting: In the bowl of an electric mixer fitted with the flat beater, beat the cream cheese, butter and salt on medium-low speed until smooth and creamy, 2 to 3 minutes. Reduce the speed to low, gradually add the confectioners’ sugar and beat until incorporated. Add the vanilla and beat just until incorporated. Do not overmix or the frosting will incorporate too much air; it should be creamy and dense, like ice cream. You will need only about half of the frosting for the cupcakes.
If you leveled the cupcakes, first spread a thin layer of frosting (called a crumb coat) on top of the cupcakes and refrigerate for 5 minutes. Then frost and decorate the cupcakes as desired. Makes 6 cupcakes.
Williams-Sonoma Kitchen.