Line bottom of three 9-inch round cake pans with greased waxed paper; set aside. Mix finely chopped roasted peanuts, flour and baking powder; set aside. Combine egg yolks and 1 cup granulated sugar; beat until thick and light colored. Add vanilla, then stir into peanut mixture. Combine egg whites and salt; beat until stiff, but not dry. Gradually add 1/2 cup granulated sugar, beating until stiff peaks form. Gently fold egg whites into peanut mixture. Pour into prepared pans. Bake at 325 F. for 30 minutes. Allow to cool for about 15 minutes. Loosen layers around edges and turn out of pans onto wire racks. Remove waxed paper. Wrap cooled layers and store at room temperature until ready to serve.
Combine confectioners sugar and whipping cream, beat until soft peaks form. Chill. When ready to serve, spread whipped cream on each cake layer and sprinkle with grated chocolate. Stack layers and garnish top with peanut halves. Makes 12 to 16 servings.