To make the base:-
Line the bottom of a 9inch springform pan with a greaseproof paper round.
Using a food processor, pulse the Lotus Biscoff biscuits into fine crumbs. Keep 3 tablespoon of crumbs aside for topping.
With the remaining crumbs add in the melted butter until combined.
Spread the crumb mixture to the prepared pan's bottom and press evenly.