Most icing used for cakes, cupcakes and other sweet treats is made with buttercream, which contains a significant amount of butter. However, knowing substitutes for butter in icing is a good idea in case you ever you run out of butter and need to ice a cake fast. The high fat content in butter is another reason to look for a substitute if you prefer healthier icing options.
While most buttercream icing recipes call for butter, some call for shortening. Vegetable shortening is made from plant fats and will make your icing a bit stiffer than butter. The fat content is still high, however. A simple shortening icing recipe combines 150 ml (2/3 cup) vegetable shortening with 150 ml (2/3 cup) milk, 5 ml (1 tsp) of salt and 15 ml (1 tbsp) of vanilla extract in a bowl. Slowly beat a 90 g (2 lb) bag of icing sugar into the mixture until it reaches the desired sweetness and thickness.
Margarine is another alternative to butter if it is transfat free, non-hydrogenated and unsalted. Margarine can replace butter block for block in a buttercream icing recipe although the taste will be different. For a basic vanilla buttercream recipe with margarine, combine 60 ml (4 tbsp) of margarine with 30 ml (2 tbsp) of milk, 5 ml (1 tsp) of vanilla extract and 500 ml (2 cups) of icing sugar.
If you really want a healthy icing, use yoghurt instead of butter in a recipe. However, the results will be vastly different from regular buttercream. The icing will have the consistency of a glaze, so you will need to use quite a bit of icing sugar if you want to thicken it up. 250 ml (1 cup) of Greek yoghurt replaces the butter in a standard recipe. Placing it in the refrigerator for at least 30 minutes also helps to thicken it up.
Although the taste will be different, substituting cream cheese for butter will create a creamy, heavy icing. Using a low-fat cream cheese also makes it healthier. Replace a block of butter in a standard recipe with 110 g (4 oz) of softened low-fat cream cheese.