01 -
Preheat oven to 160°C/320°F (140°C fan) with shelf in middle position. Prepare a 20cm/8" springform pan by turning the base upside down, buttering lightly, then pressing on a square of parchment paper. Clip into the springform pan with excess paper extending. Butter and line the sides of the pan.
02 -
Break biscuits by hand and process in a food processor until fine. Add melted butter and blitz until mixture resembles wet sand. Transfer to prepared pan, spreading across base and pressing up the sides using a flat-bottomed measuring cup.
03 -
Beat cream cheese until just smooth (about 20 seconds) without overbeating. Add flour and beat for 5 seconds until incorporated. Mix in vanilla, sour cream, sugar and lemon zest briefly until just combined.
04 -
Add eggs one at a time, beating minimally between additions. Once smooth, stop beating immediately. Gently fold in blueberries with a rubber spatula and pour into prepared crust.
05 -
Bake for 70 minutes until slightly puffed, light golden brown, and still with a slight jiggle when gently shaken. Surface should be flat without cracks.
06 -
Allow cheesecake to cool in the oven with door ajar for approximately 2 hours. Refrigerate in pan for at least 4 hours or overnight. Cake will settle with a flat surface.
07 -
Release springform sides and use parchment overhang to slide cheesecake off the base onto serving plate.
08 -
Combine 125g blueberries with vanilla, sugar and lemon juice in a saucepan. Simmer for 7 minutes until berries break down. Mix cornflour with water, stir into sauce to thicken. Add remaining blueberries and remove from heat to cool.
09 -
Adjust cooled topping consistency if needed, then spoon over cheesecake to cover completely. Refrigerate for at least 2 hours before slicing and serving.