Cut a 1/2 inch horizontal slice off the top of the cake; set slice aside. Carefully
hollow out the center of the cake, leaving a 1/2 inch shell on the bottom and sides.
Reserve removed cake for snacking or another use.
Spoon 1 cup of the whipped topping into the cake shell. Frost the sides with
1 1/2 cups whipped topping. Refrigerate until ready to serve.
Just before serving, place assorted "jewels" over whipped topping in
cake shell. Angle reserved cake slice over jewels using pretzel rod pieces to resemble
an open chest lid. Frost slice with remaining whipped toping. Decorate with miniature
candy-coated semisweet chocolate candies and licorice. Add remaining pretzels to
ends of chest for handles.