Preheat the oven to 350°F (175°C). Grease and flour the 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 cooled, slice it in half horizontally to create two layers.

Place one layer on a serving plate and spread the softened vanilla ice cream evenly on top.

Add the second layer of cake on top of the ice cream and press gently.

Spread the softened chocolate ice cream on top of the second layer.

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

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.

Slice and serve immediately.