Place twelve cupcake liners into muffin cups.
Crush cookies into crumbs. Add melted butter, then mix to combine. Press crumbs into twelve cupcake liners. Set aside.
Mix softened ice cream with chocolate chunks, cinnamon, and nutmeg. Spoon into cupcake liners. Freeze until firm, then remove from muffin pan (leaving on the cupcake liners) and place in a Ziploc or other airtight container.
To serve, peel off liners, place on a plate, and top with any or all of the toppings. You can also just serve them in the liners.
(Alternately, you can press nuts and/or crumbs into the top of the cups before freezing them.)