To make the base use a food processor to whizz up the biscuits into crumbs, or bash them with a rolling pin in a bowl
Mix in the melted butter and press the mixture into the bottom of a 23cm springform tin. Put it in the fridge for 30 minutes to set
For the cheesecake filling use a food mixer with a whisk attachment or an electric hand whisk to mix together the cream cheese, lemon curd, lemon zest, lemon extract and icing sugar until smooth with no lumps
Add the double cream and whisk until it is very thick and holds it's shape
Smooth the mixture into the tin on top of the biscuit base, then put it in the fridge overnight, or for at least 4 hours, to set
Remove from the tin and put on your serving plate. Smooth the sides with a butter knife to create a neater finish
To decorate, whip up the double cream with the icing sugar and vanilla extract, and pipe it all around the edges of the cheesecake
Pour the lemon curd into the centre and add the lemon zest on top of the cream
Serve immediately, store any leftovers in the fridge and eat within 2 days