Scoop a few dollops of ganache onto the bottom of a bread pan.
Sprinkle some graham cracker crumbs around.
Spread a layer of ice cream over the top.
Sprinkle graham cracker crumbs over the ice cream layer, and dollops of ganache. Swirl the ganache as much a little, without making the ice cream turn brown.
Repeat another layer of ice cream. Another layer of chocolate and graham cracker. Another layer of ice cream. Another layer of chocolate and graham. Ice cream again and end with just a little ganache and crumbs. (So 4 layers of ice cream if you can)
Cover and place in the freezer for 6 hours up to overnight till ice cream is a hard and scoop-able consistency.
Serve when ready. Leave leftovers in the freezer covered for up to 2 weeks.