Lemon & blueberry cheesecake slice

Name: Lemon & blueberry cheesecake slice
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Ingredients: Sweet plain biscuits; butter, melted; packet of reduced fat cream cheese (lactose free if required); Plain lactose free yoghurt; ⅓ cup caster sugar; tbsp lemon juice; Zest of 1 lemon; 1 tsp vanilla extract; cornflour (corn starch); 2 egg whites; 1 cup fresh blueberries or raspberries (can use frozen - just measure by cup not grams)