This sugar-free Neapolitan cake recipe is a secret recipe that has been adapted to be completely sugar-free. The cake is made up of three layers: chocolate, vanilla, and strawberry. Each layer is made using sugar substitutes, including stevia and erythritol. The cake is then frosted with a sugar-free buttercream frosting that is just as delicious as the traditional version. This sugar-free Neapolitan cake is perfect for anyone who is diabetic or following a low-sugar diet.