Place the biscuits in a food processor and pulse until fine. Transfer to a bowl. Melt the butter and add it to the biscuits.
Mix until fully incorporated. Transfer to a 20cm/8-inch springform pan, and press downward. Transfer the pan to the freezer while you prepare the other elements.
Add 1 cup of heavy cream to a bowl. Use a hand mixer to beat until it’s whipped. Set the bowl aside.
To another bowl, add the cream cheese. Whisk it until it softens. Add it to the whipped cream and mix until incorporated.
Place ½ cup of heavy cream in a small saucepan over low heat. Once it comes to a simmer, add the jello and whisk. Keep whisking until the powder dissolves.
Take the saucepan off the heat and pour it into the cream cheese bowl with one hand while whisking with the other. Keep whisking until no lumps remain, and all steam has escaped. You can pass the mixture through a fine sieve if you want a silky smooth cheesecake.
Take the springform pan out of the freezer and place it on the counter. Pour the lemon cheesecake over the crust and spread using a spatula. Transfer to the fridge to set for 6-12 hours.
Cut the cheesecake into 8 slices. Garnish with lemon slices or fresh mint leaves if desired. Serve cold.