In a large bowl, combine the cake mix, gelatin, eggs, oil and water; beat on low speed for 30 seconds. Beat on medium for 2 minutes. Stir in raspberries. Pour into a greased 13-inch by 9-inch baking pan. Bake at 350° for 35-40 minutes or until a toothpick inserted near the center comes out clean. Cool. For frosting, in a large bowl, fold whipped topping into raspberries. Spread over cake. Refrigerate for 2 hours before serving. Store in the refrigerator. Garnish with fresh raspberries if desired.