In a large mixing bowl, combine the softened cream cheese and unsalted butter.
Using an electric mixer, beat the cream cheese and butter together on medium speed until smooth and creamy, about 2 minutes.
Add the powdered sugar gradually while continuing to beat on low speed until fully incorporated and smooth.
Add the vanilla extract, ground cinnamon, ground nutmeg, ground ginger, and salt to the mixture.
Beat on medium speed until all spices are evenly combined and the filling is fluffy, about 1-2 minutes.
Scrape down the sides of the bowl with a spatula to ensure all ingredients are well mixed.
Use immediately as a filling for carrot cake layers or refrigerate in an airtight container until ready to use.