Grease and flour three 9x1-1/2-inch-round cake pans; set aside. Preheat oven to 350 degree F. Prepare cake mix according to package directions using the water, oil, and eggs called for. (If using white cake mix, stir in the 1 tablespoon lemon peel.) Divide batter among prepared pans. (If you have only two 9-inch cake pans, cover and chill one-third of the batter and bake it after the other layers are out of the pans.) Bake about 15 minutes or until a toothpick inserted near the center comes out clean. Let cool in pans on a wire rack for 10 minutes. Remove cakes from pans. Cool thoroughly.
For filling, in a small bowl stir together the chocolate-hazelnut spread and ricotta cheese. Place one layer of cake on a serving platter; spread top with half of the jam. Spread half of the chocolate mixture over jam. Top with another layer of cake. Spread with remaining jam and remaining chocolate mixture. Top with remaining layer of cake. In a chilled bowl beat whipping cream and powdered sugar with chilled beaters of an electric mixer on medium speed until stiff peaks form. Spread whipped cream over top and sides of cake. Top with hazelnuts. Cover; chill up to 24 hours. Makes 12 servings.