Double-Decker Knox Blox

3 envelopes Knox unflavored gelatine
3 small boxes fruit flavor gelatin
3 cups boiling water
1 cup whipping or heavy cream

In a large bowl, combine Knox unflavored gelatine with fruit flavor gelatin. Add boiling water and stir until gelatine is completely dissolved. Stir in cream. Pour into an 8- or 9-inch square pan. Chill until firm.

To serve, cut into 1-inch squares.