Preheat oven to 350 degrees. Grease a 9-inch spring form pan.

In a mixing bowl, combine the eggs, vegetable oil, and water and beat for 2 minutes. Add the cake mix and beat until well combined. Pour the batter into the prepared pan and bake for 20 minutes or until a toothpick inserted in the center comes out clean and the cake springs back when lightly touched. Let cool completely. Remove the cake from the pan and slice it in half horizontally. Clean the pan and place one half of the cake back in the pan.

Remove the ice cream from the freezer and let soften for 5 minutes or until it can be spread easily but is not melted. Put the ice cream on top of the cake layer in the pan and top with the other half of the cake. Return to the freezer for at least 2 hours or until the ice cream has frozen solidly again.

Place the chocolate chips in a heat-proof bowl. Pour the cream into a small saucepan and bring just to a boil. Pour the cream over the chocolate and let sit for 5 minutes. Whisk until the chocolate is smooth and glossy. Let cool for a few minutes.

Remove the cake from the pan and place it on a wire rack placed over a baking sheet. Pour the ganache on top of the cake and, with an off set spatula, spread it evenly over the top, letting some of the chocolate drip down the sides. Return the cake to the freezer until serving time.