A box of lemon cake mix, raspberry jam and canned frosting make it a breeze to assemble this lovely layered torte from our Test Kitchen. TIP: To split each cake layer evenly, insert toothpicks into the side of the cake layer to mark the halfway point. Wrap a length of dental floss around the cake, resting it on the toothpicks. Cross ends of the dental floss and pull gently to split the cake.