Conventional frosting provides a versatile and easy way to cover a cake, but despite its flexibility it isn’t always the perfect finish for every cake. Sometimes, for example, you might want your cake to have a simple, glossy finish. In the case of a cake topped with fruit or a layer of mousse, a shiny glaze has the further advantage of providing a layer of protection against drying. You have several ways to do this.
For fruit- or mousse-topped cakes, the shining gloss usually comes from a brushed-on glaze. Pastry chefs traditionally glazed light-colored fruit with apricot jam, heated and thinned slightly with hot water, to give a shiny surface. For dark-colored fruit, red-currant jam served the same purpose. An even glossier alternative is “miroir” — the French word for mirror — which is made from unflavored gelatin. It can be flavored or colored to suit any mousse or fruit, or simply left clear for maximum versatility. For cakes covered with fondant, or for gum paste and fondant decorations, you can make an effective glaze from equal parts light corn syrup and a clear alcohol, such as vodka.
In lieu of regular icing, you can give your entire cake a sleek, elegant, glossy appearance by glazing it with ganache. It’s made by heating heavy cream to a boil and using that to melt chocolate, then pouring the mixture over your cake before it cools. Poured fondant, a specialized form of glaze, gives cakes a gentle sheen rather than a true gloss, but it can be tinted into many pastel shades and has a pleasantly old-fashioned appearance. Conventional rolled fondant, the kind that’s used to cover and decorate elaborate special-occasion cakes, ordinarily has a matte finish. You can make it glossy instead by steaming it with a clothing steamer. The effect is temporary, but you can repeat the process if needed.
References and ResourcesJoy of Baking.com: Apricot Glaze
Good Food Gourmet: A Farewell to Summer Berries With a Raspberry Miroir Mousse Cake
The Kitchn: How to Make Chocolate Ganache for Any Dessert
King Arthur Flour: Poured Fondant Icing
Craftsy: Achieve a Glossy Finish, Come Rain or Shine