Preheat the oven to 180°C.
Mix crushed biscuits and melted butter in a bowl.
Press the mixture into the base and sides of a 23cm springform tin.
Chill the base in the fridge for 10 minutes.
Melt chocolate and butter together over a pan of simmering water.
Whisk eggs and sugar for 5-6 minutes until thick.
Fold cream and melted chocolate into the egg mixture.
Pour filling into the tin and bake for 40-50 minutes until set.
Allow the pie to cool completely.
Heat sauce ingredients in a saucepan until smooth and glossy.
Cool the sauce for 5 minutes then spread over the pie.
Chill in the fridge for 20 minutes before serving with double cream.