Source: The Betty Furness Westinghouse Cook Book

Holiday fruit cake baked in candied grapefruit shells is a delightfully original gift. It packs easily and travels well.

12 grapefruits
8 cups water
8 cups granulated sugar
2 cup corn syrup
1 tablespoon glycerin

To Prepare the Shells: Select perfect grapefruits that are clean and free from blemishes. Wash and cut slice from top of each. Remove inside of fruit with teaspoon, being careful not to break shell. Cover shells with cold salted water (1 teaspoon salt to each quart water), bring to boil, and cook five minutes. Drain, cover again with fresh water and boil five minutes. Repeat process about three times until bitter flavor is gone from peel and peel is tender, but not tender enough to break apart. Invert shells and drain on a wire rack for at least an hour, preferably overnight.

Syrup for 10 to 12 Shells There must be enough syrup to cover and float the fruit. Cook the shells in syrup until syrup gives a jelly test (about 250 degrees F). Let shells stand in syrup overnight, or longer.

Reheat and cook 10 minutes. Cool in syrup until ready to use. Drain before filling with cake mixture. Use any fruit cake batter to fill shells. Fill shells about 3/4 full.

To Cook the Cakes in Candied Shells: Steam about 1 1/2 hours. This may be done on top if the range, in the oven or the roaster. (Place filled grapefruit shells on lift-out rack in insert pan of roaster-oven. Pour 2 quarts of water in bottom of insert pan, set control at 300 degrees F for 1/2 hour, or until center of cakes are done when tested with a wooden pick. Cool.

Store in a covered container. If the confection seems dry, place a fresh orange in the container for a day or two. If properly stored, this confection will keep for a year. Serve by slicing through peel, either crosswise or lengthwise.