Tropical Knox Blox

7 envelopes Knox unflavored gelatine
1/3 cup granulated sugar
3 cups boiling water
1 (6 ounce) can frozen orange juice concentrate
2 (11 ounce) cans Mandarin oranges, undrained
1/2 cup white cr me de cacao

In a large bowl, mix gelatine with sugar. Add boiling water and stir until gelatine is completely dissolved. Stir in orange juice concentrate, Mandarin oranges with juice and cr me de cacao. Pour into a 13 x 9-inch baking pan and chill until firm.

To serve, cut into 1-inch squares.