In a medium bowl, stir together the crushed sugar cones, sugar and butter until evenly mixed. Press the mixture evenly on the bottom of a 9- or 10-inch springform pan (if using a 9-inch pan, make sure the sides are at least three inches high). Freeze for at least 20 minutes.
Stir the blueberry ice cream until smooth (so that all the soft/melty areas are incorporated). Spread evenly over the chilled crust. Freeze until firm, about 30 minutes.
Do the same with the vanilla ice cream and spread evenly over the blueberry ice cream layer; freeze until firm.
Finish with the strawberry ice cream - stirring to combine and then spreading evenly over the vanilla ice cream. Freeze for at least an hour before covering the top with plastic wrap, otherwise it will stick and make a mess of the top of the cake. You can also serve at this point.
Well-covered, the cake can be frozen for 1-2 weeks.
Before serving, remove the cake from the freezer and let it sit at room temp for 10-15 minutes before unmolding the sides of the pan. For easier, clean slices, run a long, thin knife under hot water and wipe clean before each slice.
Serve the cake slices with hot fudge sauce, if desired (or any other toppings worthy of an ice cream cake!).
Ice Cream Flavors: it totally goes without saying (but I'll say it anyway), but this cake is highly adaptable to different ice cream flavors so let your imagination (and grocery store options) go crazy.Plan Ahead: this recipe is shockingly easy - but you WILL need to plan time for each layer to harden in the freezer before adding the next layer.Baking Pans: If you don't have a springform pan, you could probably make this in a casserole-type dish (like a 9X13-inch maybe?) or in a cake pan. Just make sure the sides of the cake pan (if using a 9-inch) are at least 3-inches high so you can fit in all the luscious ice cream.