1 tsp. unflavored gelatin
1 c. heavy whipping cream, at least 24 hours old
4 tsp. cold water
1/4 c. powdered sugar
1/4 tsp. vanilla

Combine gelatin and water. Let stand until thick. Then place over low heat, stirring constantly, until gelatin dissolves, which takes about 3 minutes. Whip cream with 1/4 cup confectioners' sugar and 1/4 teaspoon vanilla, just until it is slightly thickened. While beating slowly, gradually add gelatin to whipped cream mixture. Whip at high speed until stiff. Cakes frosted with whipped cream should always be refrigerated.