Line the base of a 20cm springform cake tin with baking parchment.
Melt the butter in the microwave in 30-second bursts.
Meanwhile, blitz the Biscoff biscuits in a food processor to make coarse crumbs.
Transfer to a bowl, then stir through the melted butter until it has a texture like damp sand.
Tip the mixture into the lined tin, using a spoon to smooth and flatten.
Keep chilled while you make the filling.
Gently melt the Biscoff spread in a microwave-safe bowl in short bursts in the microwave, then leave to cool slightly.
Put the soft cheese in a large bowl and beat with an electric whisk to loosen.
Pour in the cream and sift over the icing sugar, then add the Biscoff spread.
Beat on a low speed for 2-3 mins until thick and smooth.
Spoon the mixture onto the chilled base, then smooth out using the back of the spoon.
Chill for 4-5 hrs or overnight.
To decorate, melt some Biscoff spread in the microwave as before and drizzle over the top of the cheesecake, then scatter over some roughly crushed biscuits.
