3Boil raisins (if using) rapidly, in the 2 cups of water, in an uncovered medium-size saucepan for 10 minutes. Transfer raisins and their liquid to a large bowl. Cool, to lukewarm. (If not using raisins, only use 1/2 cup of lukewarm water.) Stir in egg, then shortening and sugar; then, flour mixture; add nuts. Turn into prepared pan.
4Bake for 25 minutes, or until tests clean with a toothpick, in center. Cool completely, in pan on wire rack. Frost and cut into 24 squares.
5BROWN SUGAR/PENUCHE FROSTING: Melt 1/2 cup butter and add 1 cup packed brown sugar. Bring to boiling; cook, and stir 1 minute, or until slightly thick. Cool 15 minutes.
Add 1/4 cup hot milk, and beat smooth. Beat in enough of the 3 1/4 cups confectioners' sugar, for spreading consistency. Frosts one sheet cake or two 8 or 9 inch layers.
6ORANGE FROSTING: Beat 2 cups confectioners' sugar with 2 Tbs.orange juice, and 1 Tb. melted butter, in a bowl, until smooth and spreadable.