Measure out powdered sugar (by spooning it into a measuring cup and leveling it off with the back of a knife) and sift it into a large bowl (to remove any lumps). Set aside.
3 cups powdered (icing) sugar
In the bowl of a stand mixer fitted with the wire whip attachment, whip butter on medium speed until smooth (about 1 to 2 minutes).
½ cup (1 stick) unsalted butter, at room temperature
Add in cream cheese and continue to mix until smooth and well combined (about 1 to 2 minutes more), scraping down the sides of the bowl with a rubber spatula, as necessary.
1 cup (8 oz) full-fat cream cheese
Add in vanilla and salt. Mix until well combined (about 30 seconds).
1 tsp pure vanilla extract
¼ tsp kosher salt
Reduce mixer to low speed and slowly add in sifted powdered sugar.
Increase the mixer to medium speed and mix until powdered sugar is fully incorporated and frosting is smooth (about 30 seconds).
Notes
For perfectly smooth cream cheese frosting:
Bring all ingredients to room temperature so they blend easier.
Sift powdered sugar so no lumps form.
This frosting is perfectly sweet and tangy. Want it sweeter? Add more powdered sugar, ½ cup at a time, until it tastes as you like it.
You can freeze cream cheese frosting in an airtight container for up to 3 months. Simply thaw overnight and re-whip before using.