Put the biscuits in a bag and crush them with a rolling pin until they are crumbs (choose your moment as it can be fantastic therapy!) Gently melt the butter in a saucepan or microwave, then add in the biscuit crumbs. Mix well then press into the base of a loose-bottomed 17cm cake tin - if you don't have a loose bottomed cake tin then use any round dish lined with grease proof paper. Use a potato masher for a really compact job. Put in the fridge for 30 mins.
Mix the cheese, sugar, lemon and vanilla together and pour over the top of the biscuit base and chill. Top with fresh fruits.