Double line six ramekin dishes with cling film, leaving plenty of overhang. Combine the butter and biscuits in a bowl then divide equally between the prepared ramekin dishes and press down with the back of a teaspoon to form a base.
In a saucepan over a medium heat, combine half of blueberries with the caster sugar and lemon juice. Cook and mash over a low heat for 10 to 15 minutes until soft. Purée then press through a sieve into a clean saucepan. Soak the gelatine leaves in cold water for 5 to 6 minutes then drain and squeeze any excess liquid out. Add to the blueberry purée and cook over a low heat for 3 to 5 minutes until melted.
In a mixing bowl whisk the cream cheese together with the yoghurt and vanilla extract until light and fluffy. Add the blueberry purée. Divide equally between the 6 ramekin dishes and smooth the top. Chill in the fridge for 6 hours to achieve a good set.
Gently remove the individual cheesecakes from the ramekins using the cling film to help you. Place on individual serving plates. Top with remaining blueberries.