In a medium saucepan over medium heat, combine the heavy whipping cream, corn syrup, sugar, salt, butter, and vanilla. Whisk constantly until the butter is fully melted and the mixture begins to simmer.

Reduce heat to medium-low and add the chocolate chips. Stir until melted.

Whisk in the cocoa powder and continue to cook on low until fully incorporated and glossy, about 1 minute.

Place the hot fudge into an airtight container and store in the refrigerator until room temperature, 20-30 minutes. It will thicken significantly as it cools.

In a small bowl, combine the graham cracker crumbs and granulated sugar, then pour in the melted butter. Mix well until all the ingredients are fully combined. Place a 6-inch cardboard cake circle into the bottom of a 6-inch springform pan, then use a glass jar or cup to press the graham cracker crust evenly on top of the cardboard cake circle and into the sides of the pan. Refrigerate the crust in the springform pan until you're ready to assemble the ice cream cake.

Wait to make the ice cream layers until right before you're ready to assemble the cake. Place a large metal or glass bowl into the refrigerator for at least 20 minutes to chill before you get started.

Melt the semi-sweet chocolate chips in the microwave in 20-second intervals, stirring after each one until the chocolate chips are fully melted. Allow to cool completely to room temperature, about 15-20 minutes.

Add the heavy whipping cream and 2 teaspoons of the vanilla extract into the chilled bowl, then whip it with a hand mixer on high speed until stiff peaks form, 3-4 minutes. You can alternatively use a stand mixer with the whisk attachment for this part. Place the whipped cream into the refrigerator while you move on to the next step.

Divide the sweetened condensed milk evenly between two medium bowls. To one bowl, whisk in the melted and cooled semi-sweet chocolate. To the second bowl, whisk in the marshmallow fluff.

Divide the whipping cream evenly between the two bowls you created in the previous step. Fold each sweetened condensed milk mixture together with the divided whipped cream to create chocolate ice cream and marshmallow ice cream. Fold the toasted mini marshmallows into the marshmallow ice cream mixture.

Un-latch the springform pan and place a sheet of acetate between the outer edge of the graham cracker crust and the inside of the pan. Re-latch the springform pan and tape the acetate together once it's the same diameter as the pie crust.

Reserve about ⅓ Cup of hot fudge sauce for the decorative drip, then pour the rest onto the graham cracker crust. Smooth with a rubber spatula to create an even layer.

Add the chocolate ice cream on top of the hot fudge layer and smooth with a rubber spatula.

Add about ⅓ Cup of the crumbled graham crackers on top of the chocolate ice cream before adding the marshmallow ice cream on top and smoothing it down with a rubber spatula.

Freeze the s'mores ice cream cake for at least 6 hours. When you're ready to serve it, remove the cake from the springform pan and unwrap the acetate.

Re-heat the hot fudge sauce in the microwave in 10-second intervals until it reaches room temperature, then use it to create a decorative half drip around the top edge of the cake. Garnish with more graham cracker crumbs and toasted mini marshmallows.