ICING VS. FROSTING
Standard icing is made with powdered sugar and liquid — cream or milk, citrus juice, or liqueur — mixed to a smooth consistency. You can add melted butter or vanilla extract for additional flavor. Standard icing is thick enough to decorate a cookie but thin enough to pour or drizzle over cakes. It tends to set quickly and harden when dry. Food coloring can be added to make it colorful.
Royal icing is powdered sugar, egg whites (or meringue powder), and flavorings; the egg whites give it more stability than standard icing. Royal icing is most commonly used for cookie decorations; it can act as edible glue to hold gingerbread houses together and secure candy pieces and decorations to the gingerbread. It dries to a hard, shiny, candy-like finish.
Fondant is an icing made with powdered sugar, water, butter, and gelatin (or marshmallows). There are two different types of fondant: poured and rolled. Poured is melted and poured over cakes. Rolled is draped over a cake; it can also be molded or cut into elaborate shapes for decoration.
Frosting is made by whipping a cream base, like butter, with powdered sugar until light and fluffy. It is thicker than icing.
Buttercreams are popular frostings used on birthday cakes and layer cakes. American buttercream, also known as plain or quick buttercream, calls for mixing powdered sugar with butter, and sometimes milk or heavy cream and vanilla — it doesn’t use any egg whites. Swiss, Italian, and French buttercreams all contain eggs. Swiss and Italian buttercreams are made with meringue; French buttercream uses egg yolks rather than whites.
Whipped cream frosting is a bit lighter than American buttercream frosting because there is no butter. It is made with heavy whipping cream and powdered sugar. Whipped cream frosting is used on desserts that are already sweet, like cheesecakes. Cream cheese frosting tops red velvet and carrot cakes. It’s made the same way as traditional American buttercream, but with butter and cream cheese.
Ganache — a 1:1 mixture of chocolate melted into heavy cream — works as a filling and frosting; it can even be poured and makes a beautiful drip for cakes. You can use semi-sweet chocolate (traditional), bittersweet chocolate, milk chocolate, or white chocolate as your ganache base. A white chocolate ganache base can be colored with food coloring.