• 180 g graham-cracker crumbs
• 50 g caster sugar
• 85 g unsalted butter, melted
• 10–15 ml filtered water (add only if crumbs look dry)
• 800 g chocolate ice cream, slightly softened
• 100 g mini marshmallows (enough to blanket the top)
  

1. Make the crust. Stir the crumbs and sugar together, then pour in the melted butter. Mix until the texture resembles damp sand; if it still won’t clump when pinched, drizzle in filtered water and mix again. Press the mixture firmly over the base and up the sides of a 23 cm pie dish. Chill for 30 minutes.
2. Add the ice cream. Dip a small ice-cream scoop into the hot water, shake off excess, then pack the softened chocolate ice cream into the chilled crust. Smooth the surface with a spatula. Cover completely with the mini marshmallows, pressing lightly so they stick.
3. Freeze. Place the pie in the freezer for at least 2 hours, or until the ice cream is very firm.
4. Toast the marshmallows. Quickly brown the topping with a blow-torch, moving the flame constantly. (If you don’t have a torch, set the pie on a tray under a very hot grill/broiler for 30–60 seconds, watching closely.) Return the pie to the freezer for at least 3 hours so the topping firms up again.
5. Serve. Remove the pie from the freezer about 5 minutes before slicing. Dip a sharp knife in the hot water, wipe it dry, and cut clean wedges.

Storage

Wrap tightly and freeze for up to 1 month; return any leftover slices to the freezer straight after serving.