Put biscuits and butter in a food processor and pulse until you have a pasty mixture.
Grease a 9-inch springform pan with butter, pour in the cookie mixture and pack in very tightly and evenly with the back of a spoon. Place in the fridge while preparing the rest of the recipe.
Place gelatine sheets in cold water for 5 minutes.
Squeeze the gelatine sheets and put them in a heated pan with 6 tbsp of water. Stir for a few seconds or until dissolved. Set aside and let cool.
Using a hand mixer or a stand mixer fitted with a whisk or paddle attachment, beat the cream cheese, greek yogurt, powdered sugar, juice and lemon zest until perfectly smooth and creamy. Add the melted gelatine and mix well until combined.
Remove crust from the fridge and spread filling into crust. Smooth down the top with a spatula, making it even.
Refrigerate for at least 6-8 hours, ideally overnight. The longer refrigerated, the nicer the no-bake cheesecake will set up.
Top with the raspberry jam and put in the fridge until serving.
Use a thin, sharp knife to carefully loosen the chilled cheesecake from the rim of the springform pan, then remove the rim. Using a clean sharp knife, cut into slices for serving. For neat slices, wipe the knife clean between each slice.
Store leftover cheesecake in the refrigerator for up to 5 days.