When you're in a pinch, you can use margarine in place of butter in cream cheese frosting, but don't expect the results to be exactly the same. Margarine doesn't blend with quite the same smoothness as butter. You might not notice this in a baked good, but you'll definitely notice it in frosting. Margarine also lacks butter's rich, but subtle, flavor. Use margarine -- or even shortening -- as a last resort in this thick, creamy frosting.
You can substitute margarine for butter in cream cheese frosting. In baked goods, you might not notice the difference in taste when you substitute one for the other, but you'll probably be able to discern it in cream cheese frosting. Butter and margarine just don't taste the same. If you don't mind the taste of margarine, go ahead and use it in cream cheese frosting. If, on the other hand, you love the taste of butter and don't like margarine, you'll probably be disappointed.
Creamy and Smooth
Margarine is a bit more difficult to work with than butter. If it's too hard, you'll end up with a grainy frosting. If it's too soft, the frosting will be greasy, rather than creamy. Let margarine sit at room temperature until it's very soft, or microwave it for a few seconds. Allow the cream cheese to soften at room temperature as well. Beat the cream cheese and margarine together until they're creamy and smooth. Only then should you add the sifted powdered sugar.
The main advantage to using margarine instead of butter in cream cheese frosting is the difference in cost. Butter can cost double the price of margarine, depending on the brands you use. Another potential benefit relates to your health. Butter contains about 100 calories per tablespoon and 11 grams of fat, including 7 grams of saturated fat. Margarine contains 87 calories per tablespoon and 10 grams of fat, including 2 grams of saturated fat. Keep in mind, though, that margarine products vary in their fat contents and calories. Some kinds of margarine contain trans fats, which may be even less healthful than saturated fats, so be sure to read the label if this is a concern.
If you're going to the time and expense to make cream cheese frosting, splurge and use real butter. In this frosting, nothing compares to its taste and texture. Trim pennies and calories elsewhere.