1. Grease three 9-inch layer cakepans; line with wax paper; grease paper.
2. Sift cake flour, baking powder and salt onto wax paper.
3. Beat butter or margarine with sugar until fluffy in large bowl with an electric mixer at high speed. Beat in eggs, one at a time, until fluffy; stir in vanilla.
4. Stir in flour mixture, a third at a time, alternately with milk; fold in walnuts. Pour batter into prepared pans, dividing evenly.
5. Bake in moderate oven (375°) 30 minutes, or until centers spring back when lightly pressed with fingertip.
6. Cool in pans on wire racks 10 minutes. Loosen around edges with a knife; turn out onto racks; peel off paper; cool layers completely.
7. Put layers together with currant jelly on a serving plate; frost side and top of cake with seafoam frosting Decorate with additional chopped walnuts, if you wish.