1) Using a large mixing bowl, place biscuit crumbs and melted butter. Mix until the ingredients are well blended and moist. Keep mixture at room temperature until needed for pie shells.
2) Lightly spray 2 pie tins with vegetable oil. Place the prepared crust into the pie tins and press firmly on the bottom and sides of each tin, forming a smooth and even thickness approximately 1/2-cm thick. Use a ladle to even out the crusts. Place the pie crusts in freezer before ice cream can be placed into crusts.
3) Equally portion the ice cream into the pie shells. Mound the ice cream to create a 8-cm high dome. Use a glove and napkin to help with this process. Place pies on a sheet tray and place in the freezer for approximately 6 hours or more.
4) To serve, drizzle with chocolate sauce and sprinkle with more biscuit crumbs and chopped nuts, if desired.