In a stand mixer or using a hand mixer, beat the cream cheese and butter on medium speed for 1-2 minutes, until light and fluffy.
Gradually add 3 ½ cups of powdered sugar, lemon juice, salt and the lemon zest, mixing on low until combined. Increase the speed to high and beat for 2-3 minutes. Adjust the sweetness by adding more powdered sugar if desired. If too thick, thin with 2-4 teaspoons of milk or heavy cream.
Keep covered and store in the refrigerator for up to 1 week or in the freezer for up to 3 months. After chilling or freezing, let it thaw in the refrigerator and come to room temperature. Then, beat the frosting for a few seconds to restore its creamy texture. If it’s still too stiff, add a small amount of milk or heavy cream and mix until smooth.
