Line the base and sides of a 20cm-24cm spring form tin with baking paper.

For the base, melt the butter in the microwave on short bursts or in a small saucepan over a medium heat.

Blitz biscuits in a food processor to a small crumb, add the butter, and mix until combined. Transfer to the tin and press down firmly and evenly over the base. Place in the fridge to chill.

To make the cheesecake filling, finely chop milk and dark chocolate and place in a large heatproof bowl. Melt in short bursts in a microwave (3 x 30 sec at 1000W) or over a pan of gently simmering water, stirring gently.

Place the cream cheese, mascarpone, icing sugar and malt extract in a bowl of a food processor and process on high speed until combined and fluffy. Add the melted chocolate and whiz again until combined, smooth and silky.

Add the double cream and process on medium speed just enough to incorporate the cream into the mixture.

Pour the filling on to the biscuit base, smooth over and chill in the fridge for at least 6 hours or overnight.

To make the chocolate top, finely chop chocolate and place in a large heatproof bowl. Melt in short bursts in a microwave (2 x 30 sec at 1000W) or over a pan of gently simmering water, stirring gently. Add double cream and malt extract and mix until combined.

Remove the cheesecake from the tin, and spread the melted chocolate on top and allow to cool.

Store in the fridge for up to 3 days.