1. As soon as your butter has melted, mix with the biscuits and sugar ensuring all of the butter has combined with the biscuit.
2. Empty all of the biscuit into a 23cm springform cake tin and push into all of the edges. Place in the fridge and chill while you crack on with the remaining stages.
3. Mix together your mascarpone, cream, condensed milk and lemon zest then slowly add a little of the lemon juice a bit at a time until the mixture thickens.
4. Remove your chilled base from the fridge, pour on top of the biscuit based and smooth out the top.
5. Place back in the fridge for around 3hrs to full set your cheese cake.