Preheat the oven to 350°F (175°C). Grease and flour a 9-inch round cake pan.

In a mixing bowl, combine the chocolate cake mix, water, vegetable oil, and eggs. Mix until smooth.

Pour the batter into the prepared cake pan and bake for 25-30 minutes or until a toothpick comes out clean.

Allow the cake to cool completely in the pan before removing.

Once the cake is cool, slice it in half horizontally to create two layers.

Place one layer of cake on a serving plate. Spread the softened vanilla ice cream evenly over the top.

Add the second layer of cake on top of the vanilla ice cream. Spread the softened chocolate ice cream over this layer.

Cover the cake with plastic wrap and freeze for at least 2 hours to firm up the ice cream.

Remove the cake from the freezer and frost the top and sides with whipped cream.

Drizzle chocolate syrup over the top and sprinkle with chocolate shavings.

Return the cake to the freezer for 30 minutes before serving.