Preheat oven to 350F (175C). Spray two 8” round cake pans with baking spray (or grease and flour them) and line the bottoms with parchment paper. Set aside.

In a large mixing bowl, whisk together sugar, flour, cocoa powder, cornstarch, baking powder, baking soda, and salt.

Add canola oil, egg, and vanilla extract and stir until completely combined/all the dry ingredients have been moistened (I like to use an electric mixer for this step but it may be done by hand, just a bit more work!).

Stir in milk until batter is uniform and completely combined.

Slowly drizzle in hot coffee or hot water, stirring until well-combined. Be sure to scrape the sides and bottom of the bowl and ensure that the batter is uniform and smooth. Batter will be thin – this is normal!

Evenly divide batter into prepared cake pans. Transfer to center rack of 350F (175C) preheated oven and bake 30 minutes or until a toothpick inserted in center comes out clean or with a few moist, fudgy crumbs. Allow cakes to cool in cake pan for 15 minutes then run a knife around the edge and carefully invert onto a cooling rack to cool completely before proceeding.

Once cakes are cooled, place in freezer while you begin to prepare ice cream (if you will be storing the cakes longer than an hour, wrap them tightly in plastic wrap before freezing).

Combine condensed milk, vanilla extract, and salt in a large bowl and whisk to combine.

Pour cold heavy cream into a separate large mixing bowl and use an electric mixer to beat to stiff peaks (mixture should have greatly increased in volume and have a thick, fluffy consistency, like cool whip. If you lift a spoon or the beaters out of the cream, the peak that forms should be stiff and hold its shape without melting back down or folding over).

Add whipped cream to condensed milk mixture and add sprinkles. Use a spatula to gently fold together ingredients until uniform consistency.

Remove one cake layer from the freezer (unwrap if needed) and place on serving platter. If your cake collar is taller than 6”, trim it or it will be difficult to add your second cake layer.

Wrap cake collar securely, tightly around the first cake layer and secure with tape. The collar should be straight up and down (don’t accidentally make it cone-shaped/skinnier at the top) and should overlap itself by several inches. Once you have secured the cake collar do not remove it until all layers have been frozen overnight.

Pour ice cream over the first cake layer and smooth the surface with a spatula.

Unwrap remaining cake layer and carefully, gently place over the ice cream.

Cover the exposed layer by placing plastic wrap directly against the surface of the cake and return to the freezer to chill overnight before decorating.

To decorate, prepare stabilized whipped cream frosting according to recipe(prepare just before removing cake) and decorate as desired.

To serve, allow ice cream cake to sit at room temperature for 15-20 minutes before slicing and/or run a large, sharp knife under very hot water and then wipe dry before slicing. Cake may be served immediately, or stored in the freezer until ready to serve. Leftovers must be kept frozen.