Allow the ice cream to sit at room temperature while you prepare the cookie "crust".
Prepare "crust" but arranging cookie pieces on the bottom of a springform pan. Start with cookie halves, then fill in with smaller pieces as needed.
Scoop slightly softened ice cream onto the "crust" and use an offset spatula to smooth as needed. I only used about 3/4 of the carton of ice cream, but you can decide how thick you want the ice cream layer. Immediately place ice cream "cake" into the freezer to set up.
When the ice cream has set up, but is not frozen hard, add a layer of cookies as the top "crust". Press down into the ice cream slightly (as needed). Return entire dessert to the freezer to set up fully before serving (4 hours or overnight).
Once the ice cream "cake" is fully frozen, remove the outer ring of the springform pan, and with one hand on the top of the cookie cake, and one hand on the bottom of the springform pan, roll the outer edge of the ice cream "cake" onto a plate of mini chocolate chips. Return to the freezer until ready to serve.
Before serving, prepare fudge sauce by heating the heavy cream in a bowl in the microwave until hot, but not boiling. Remove from microwave and add semi-sweet chocolate chips. Stir gently until the chocolate has melted and is fully incorporated. Move to the fridge to cool and thicken slightly. If making the fudge sauce ahead of time, store in the fridge and it can be easily re-heated in the microwave just before serving.