In a large mixing bowl using an electric hand mixer, beat together the cream cheese, pumpkin, granulated sugar, brown sugar, pumpkin pie spice, vanilla and salt at medium speed until well combined. Beat in the sour cream on low.
24 oz (680 grams) cream cheese, 15 oz (425 grams) pumpkin puree, 3/4 cup (150 grams) granulated sugar, 1/2 cup (100 grams) dark brown sugar, 1 tablespoon pumpkin pie spice, 2 teaspoons vanilla extract, 1/8 teaspoon salt, 1/3 cup (80 ml) sour cream