Makes enough to decorate the top of one 9-inch cheesecake (double the recipe to frost and decorate the top and sides of one 9-inch cake).

Steps

1. Place the gelatin in a heatproof measuring cup, stir in the cold water, and let stand until it swells and thickens (this takes only about 1 minute). Cook the gelatin in the microwave on high for about 30 seconds or over a pan of simmering water for about 1 minute, until clear and completely melted.
2. In a medium-size bowl, whip the cream with an electric mixer on high until it thickens and soft peaks just begin to form. With the mixer still running, add the sugar and beat just until the cream stands up in peaks (don’t overmix or the cream will curdle). Beat in the vanilla. Now, add the melted gelatin all at once and beat until thoroughly incorporated. Refrigerate for at least 30 minutes but not more than 1 hour. Use immediately as a cake filling or frosting or refrigerate.
3. For whipped cream rosettes: Fit a pastry bag with a large closed-star tip (#133) or a large open-star tip (#199). Half-fill the bag with the whipped cream and pipe large rosettes all around the top or bottom edge of the cake. For smaller decorative stars and rosettes, use a medium closed-star tip (such as #27, #31 or #35) or a medium open-star tip (such as #22 or #32). The closed-star tips create deeper grooves and more details than the open-star ones, but both work fine. Put the cake in the freezer for 30 minutes to set the decorations. Transfer to the refrigerator until time to serve.