1 cup shortening**
1 cup white sugar
1/2 cup packed light brown sugar
1 tablespoon cornstarch
1 egg
3/4 cup milk
1 teaspoon vanilla extract
Heat shortening and white sugar in a large saucepan over medium heat. Cook, stirring constantly, for 1 minute or until sugar is dissolved. Remove from heat; stir in brown sugar and cornstarch. Stir until mixture is thickened.
Beat egg in small mixer bowl. Gradually beat in milk, mixing just until incorporated. Stir in vanilla extract. Pour gradually into greased and shallow baking pans; 5 inches apart.
Bake a 1/3-inch-thick layer in the center of a greased and ungreased 9-in. x 9-in. x 2-in. x 2-in. baking pans. Bake in preheated oven for 1 hour, or until toothpick inserted into top comes out clean. Cool slightly before removing from pans. Cool completely in refrigerator.