1 1/2 cup raisins 1 1/2 teaspoon baking soda 1 1/2 cup boiling water 2 1/4 cups sifted unbleached flour 1 teaspoon baking powder 1/2 teaspoon salt 1 cup shortening 1 1/2 cup sugar 3 large eggs 1 teaspoon vanilla extract 1/2 cup chopped walnuts ***SEAFOAM ICING*** 2 large egg whites 1 1/2 cup brown sugar, firmly packed 1/3 cup water 1/8 teaspoon cream of tartar 1/8 teaspoon salt 1 teaspoon vanilla extract
Grind the raisins in a food processor or grinder using the medium blade. Combine the ground raisins, baking soda and boiling water in a bowl and set aside to cool to lukewarm.
In another bowl, sift the flour, baking powder, and salt together and set aside.
Cream the shortening and sugar together in a large mixing bowl until light and fluffy, using an electric mixer set and medium speed. Add the eggs, one at a time, beating well after each addition. Blend in the vanilla extract.
With the mixer set on low speed, add the dry ingredients alternately with the raisin mixture, beating well after each addition. Stir in the walnuts. Pour the batter into a greased and waxed paper lined 13 X 9 X 2-inch baking pan.
Bake in a preheated 375 degrees F oven for 35 to 40 minutes or until the cake tests done. Cool in the pan on a wore rack for 10 minutes and then remove the cake from the pan to finish cooling on the rack. Frost the sides and top with the seafoam frosting.
SEAFOAM ICING: Combine the egg whites, brown sugar, water, cream of tartar and salt in the top of a double boiler. Beat for one minute, using an electric mixer at high speed and then place over simmering water.
Cook for 7 minutes, beating constantly with the mixer set at high speed, until soft glossy peaks form. Remove from the simmering water and blend in the vanilla extract.