1½ cups (3 sticks) unsalted butter, softened (see baker's note below)
½ cup trans-fat free shortening such as Crisco or high-ratio shortening (plain, not butter flavored)
¼ teaspoon salt
2 pounds powdered sugar, divided
1/3 cup sour cream, divided (not reduced or nonfat varieties); plus more if needed
1/3 cup heavy whipping cream, divided
2½ tablespoons orange liqueur
In the bowl of an electric stand mixer, beat butter and shortening on medium speed until light in color and well combined, about 1 minute. Add salt and beat 10 seconds. Scrape bowl very well.
Add half the powdered sugar, half the sour cream and half of the heavy whipping cream to the butter/shortening; beat on low speed 30 seconds. Scrape bowl very well. Increase speed to medium and beat 30 seconds. Scrape bowl very well.
Add remaining powdered sugar, sour cream, heavy whipping cream and orange liqueur; mix 30 seconds on low speed to combine. Scrape bowl well. Increase speed to high and beat 1 minute. Scrape bowl well. If frosting is too stiff, add 1 to 2 tablespoons more of sour cream. Beat on high speed another 2 to 2½ minutes until very smooth and light. Keep tightly covered in the refrigerator up to 2 weeks. Keeps up to 3 monthly tightly covered and sealed in the freezer.
Makes 6 cups.
Variation: For carrot or spice cake, substitute ½ cup cream cheese for ½ cup of the butter.
Baker's hint: Use only unsalted butter. Salted butter will offset the salt in this recipe.
Nutrition values per 3-tablespoon serving: 233 calories; 13 g fat (7 g saturated fat), 29 g carbohydrates, trace amount fiber, trace amount protein, 28 mg cholesterol, 20 mg sodium.