To make the cake:

1. Prepare an 8-inch cake pan with a parchment paper circle in the bottom and grease the sides. Preheat oven to 300°F (148°C).
2. Add the dry ingredients to a large bowl and whisk together to combine.
3. Add the egg, milk and vegetable oil to the dry ingredients and mix until well combined.
4. Add the vanilla extract and hot water and whisk together to until well combined. The batter will be very thin.
5. Add the batter to the prepared cake pan and bake for 35-40 minutes, or until a toothpick comes out with a few crumbs.
6. Remove cake from oven and allow to cool for about 5 minutes, then remove to cooling rack to cool completely.

To make the crunchies and chocolate fudge filling:

1. To make the crunchies, preheat oven to 350 degrees. Line a cookie sheet with parchment paper or a silicone baking mat and set aside.
2. Combine the Oreo crumbs and melted butter and stir until well combined. Spread the crumbs evenly onto the prepared cookie sheet. Bake for 8-10 minutes, then allow to cool. Use your fingers to break any big clumps into smaller ones. Set aside.
3. To make the fudge layer, add the chocolate chips, corn syrup and vanilla extract to a medium sized bowl.
4. Heat the heavy whipping cream just until it begins to boil, then pour it over the chocolate chips. Allow to sit for 2-3 minutes, then whisk until smooth. Set aside.

To build the cake:

1. Set your ice cream out for 15-20 minutes before you need it to let it soften, but not melt.
2. Line your 8-inch pan with two pieces of clear wrap, one on top of the other going in opposite directions. The pieces of clear wrap should be long enough that you can use them later to lift the cake out of the pan. Press the clear wrap into the pan and press against the bottom and sides to flatten it.
3. Put the ice cream in a large bowl and stir until creamy and smooth, then pour the ice cream into the lined pan and spread it into an even layer.
4. Add the chocolate cookie crunchies on top of the ice cream layer and spread evenly.
5. Add the chocolate fudge mixture on top of the cookie crunchies and spread evenly. Set the pan in the freezer for about 10 minutes so that the chocolate fudge firms up a touch.
6. Place the chocolate cake on top of the chocolate fudge layer. The part of the cake that’s sticking up will become the bottom of the ice cream cake. Use the clear wrap hanging over the sides of the pan to wrap up the cake (cover it with more clear wrap, if needed), then freeze for 3-4 hours or until completely firm.

To finish the cake:

1. When the cake is frozen and firm, use the clear wrap to loosen and lift the cake out of the pan. Turn it over onto a cardboard cake circle or a serving platter. Remove the clear wrap from the top of the ice cream.
2. To make the whipped cream frosting, add the heavy whipping cream, powdered sugar and vanilla extract to a large mixer bowl and whip on high speed until stiff peaks form.
3. Frost the cake with the whipped cream, working quickly so that the ice cream doesn’t melt. Press the additional mini chocolate chips into the bottom of the cake, then immediately place in the freezer.
4. To make the chocolate ganache, add the chocolate chips to a medium sized bowl. Heat the heavy whipping cream just until it begins to boil, then pour it over the chocolate chips. Allow to sit for 2-3 minutes, the whisk until smooth.
5. Use the chocolate ganache to add the chocolate drip to the cake. Feel free to check out my tutorial for two methods of adding the chocolate drip.
6. Use the remaining whipped cream to pipe shells around the top edge of the cake and garnish with some cookie dough or other decorations to reflect the ice cream inside the cake. Store the cake in the freezer until ready to serve. If you have room in your freezer, store it in an air tight container. The cake is best if eaten within a week or so.