Put the caramel biscuits in a food processor and blitz to crumbs. Add the melted butter and blitz again until well combined. Use the biscuit crumbs to line a deep 22cm fluted tart tin, pressing the crumbs into the base and up the sides with the back of a spoon until really compact. Chill for 30 mins while you prepare the filling.
Remove the ice cream from the freezer 20 mins before you’re ready to use it. Tip the raspberries into a bowl, reserving a handful, and lightly crush about half with the back of a fork until juicy. Once the ice cream has softened, tip into another bowl and mash with the back of a spoon until pliable but not totally defrosted. Add the raspberries and half the Honeycomb, then ripple together.
Remove the tart case from the fridge and tip the raspberry ice cream mixture into the centre, smoothing out to the edges. Top with the reserved raspberries and honeycomb, pushing them down into the ice cream layer a little, then freeze for 4 hrs until frozen solid.
To make a caramel sauce, put the cream, sugar and butter in a saucepan with a good pinch of salt, and bring to a simmer. Bubble for 5 mins until it’s the consistency of caramel, then cool for 2 mins before serving with slices of the pie. Will keep for 1 week.