Make a colored mirror for the top of the cake

To make a shiny, colored mirror for the top of a frosted cake, combine 2 teaspoons of gelatin with 2 tablespoons water and let stand for 10 minutes to soften the gelatin. In a small saucepan, combine ⅓ cup strained fruit puree and ⅔ cup strained apricot or other fruit preserves and heat almost to a simmer. Remove from the heat and immediately add the gelatin and its soaking liquid, stirring until the gelatin dissolves. Let cool until just slightly warm. Meanwhile, place a cake ring or a strip of doubled aluminum foil on the top of the cake to contain the mirror. When the fruit mixture has cooled, but is still pourable, pour it on the top of the cake inside the ring. Let stand for about 25 minutes, or until the mirror has set, and then remove the ring.