Japanese Style Lemon Rare Cheesecake (no bake)

Name: Japanese Style Lemon Rare Cheesecake (no bake)
Prep time: 4 h 20 min
Total time: 4 h 20 min
Cuisine: Japanese
Ingredients: 15cm / 6" Cake tin (springform or one with removable base is best); Parchment or baking paper to line the base; Sieve (optional); 70g plain rich tea biscuits/graham crackers; 50g unsalted butter; Zest of 1 lemon; 7g (2 slightly heaped tsp) gelatin powder; 60ml cold water; 300g cream cheese; 300g plain yogurt; 90g caster sugar; Juice of 1/2 lemon; 1 tsp vanilla essence (or 1/2 tsp vanilla extract)