Cream together 1/2 cup shortening, 3/4 cup sugar, and 2 eggs until light and fluffy. Sift together 1 1/2 cups sifted all purpose flour, 3/4 teaspoon salt, and 2 teaspoon baking powder. Add to creamed mixture alternately with 2/3 cup milk, beating well after each addition. Spoon 1/3 of batter into well greased 6 1/2 cup ring mold or 9 x 9 x 2 inch pan. Mix 1/3 cup presweetened instant cocoa powder and 1/3 cup broken walnuts; sprinkle half over batter in pan. Repeat layers, ending with batter. Bake at 350 degrees for 35 minutes. Let stand 5 minutes; turn out of mold, serve warm.