NOTE: 8-inch springform pans are best for building this cake so that you can easily remove the cake once it’s been assembled. If you do not have a springform pan, line your pan with clear wrap before adding your parchment paper and cake board. You can use the clear warp to lift your cake out of the pan once it’s assembled and frozen. You want to make your cake layers in the same pan you’ll use for layering the ice cream and cake together so that they cake layers fit in the final pan you use for layering. In lou of using a cake pan to build the cake, you could also use cake collars.

TO MAKE THE CAKE:

1. Preheat the oven to 350°F (176°C). Line the bottom of two 8-inch cake pans with parchment paper and grease the sides.
2. In a large mixer bowl, combine the first 5 ingredients for the cake.
3. Add the egg, buttermilk, oil and vanilla and mix until smooth.
4. Add the boiling water and mix until smooth. Batter will be thin.
5. Divide the batter between the prepared cake pans and bake for 25-30 minutes, or until a toothpick inserted into the middle of the cake comes out with a few crumbs.
6. Remove cake from oven and allow to cool for 3-4 minutes, then remove cake from pan to a cooling rack to cool completely.

TO MAKE THE ICE CREAM:

7. Once the cake has cooled, make the ice cream. In a large mixer bowl, combine the cream cheese and sugar until smooth.
8. Add the milk and vanilla extract and mix until well combined.
9. In another mixer bowl, add whip the heavy whipping cream and powdered sugar until stiff peaks form.
10. Gently fold about 1/3 of the whipped cream into the cream cheese mixture until combined, then fold in the remaining whipped cream.
11. Gently fold in the graham crackers until combined throughout
12. Gently fold in the marshmallow fluff, so that there are ribbons of marshmallow fluff through the ice cream. Do not mix until completely combined.

ASSEMBLY:

13. Line the sides of an 8-inch springform pan with parchment paper. The parchment paper should stick up above the top edge of the pan, since the cake will probably be a little taller than your pan (see example). If you want, put a cardboard cake circle in the bottom of the pan. If not using a springform pan, you pan put some plastic wrap in the bottom of the pan and up the sides and use it to lift the cake out of the pan when it’s done.
NOTE: You should be using the same 8-inch pan you used for the cake. Not all 8-inch pans are exactly the same size. Your cake needs to fit in this pan.
14. Cut the dome off of the tops of the cake layers, then place the first cake layer into the bottom of the pan.
15. For the chocolate fudge layer, place the chocolate chips, corn syrup and vanilla extract in a medium sized bowl.
16. Microwave the heavy whipping cream until it begins to boil, then pour over the chocolate chips. Allow to sit for 3-5 minutes, then whisk until smooth.
17. Spread half of the marshmallows into an even layer on top of the chocolate cake.
18. Pour half of the chocolate fudge over the marshmallows and spread evenly.
19. Spread about half of the ice cream mixture into an even layer over the chocolate fudge.
20. Place the second layer of cake on top of the ice cream, then repeat steps 16-18.
21. Allow the ice cream cake to freeze completely, 6-8 hours. Once frozen, remove from springform pan and remove parchment paper from sides.
22. To make the whipped cream frosting, whip the heavy whipping cream, powdered sugar, cocoa and vanilla extract until stiff peaks form.
23. Frost the outside of the cake with the whipped cream, then pipe a border around the top edge.
24. To finish off the cake, press crumbled graham cracker crumbs onto the sides of the cake and top it will marshmallows and a chocolate drizzle. You can toast the marshmallows on top with a kitchen torch, if you have one.
25. Freeze the cake until ready to serve. This cake doesn’t freeze as firm as some others, so you don’t need to let it sit out to thaw before serving.