Blitz the biscuits in a food processor till they are a fine crumb. Melt the butter separately and then mix into the biscuits.
Press the biscuits into the bottom of an 8"/20cm deep springform tin and make sure its firmly pressed down. Refrigerate for now!
For the Cheesecake Filling
Get the gelatine leaves, and soak them in COLD water for five minutes. They just need to be submerged into the cold water to be soaked.
Once they are soaked, add the gin, tonic water and caster sugar into a pan and heat so the sugar dissolves.
Once its dissolved, take the gelatine leaves out of the cold water, squeeze the excess water out, and add to the hot gin liquid. Mix so that the gelatine leaves dissolve fully. Let the mixture cool for a few minutes, stiring often.
In your stand mixer with a whisk attachment, add your cream cheese, icing sugar, and lime juice. Whisk together until smooth.
Whilst whisking slowly, pour in the gin liquid slowly so that its incorporating as you whisk. Once all whisked in, whisk for a minute until smooth.
Add in your double cream and whisk again until smooth.
Add the mixture to the tin, and smooth over. Leave to set in the fridge for 5-6 hours, or preferably over night.
For the Decoration
Whisk together the double cream and icing sugar until smooth. Pipe onto your cheesecake in swirls, and add a slice of lime per swirl.
Sprinkle the zest of a lime on top of the cheesecake, and if you want (for decoration only) add a little straw for decoration!
Notes
For my cheesecakes, I don't personally line or grease my tins, but you can if you want to. When removing mine, I just run a knife underneath the cheesecake, and it lifts off the base.
I used gelatine in this recipe because there was a lot of liquid to add the flavour in. If you'd rather not use gelatine, you can use vege-gels which now exist as a vegetarian alternative (follow its packet instructions), or even use 3tsps of G&T flavouring that you can buy at Sainsbury's now!