Preheat oven to 160°C/320°F (140°C fan).

Prepare pan - Get a 20cm/8" springform cake tin. Turn the base UPSIDE DOWN (Note 4), butter lightly and place a square piece of parchment/baking paper on the base. Then clip into the springform pan - excess paper will stick out, see photos in post and video. Butter and line the side of the pan.

Blitz - Break up biscuits roughly by hand and place in a food processor. Blitz until fine crumbs (Note 5). Add butter, briefly blitz until dispersed and it resembles wet sand.

Press into pan - Pour into the prepared cake tin. Use a spatula to roughly spread it out over the base and up the walls. Use something with a flat base and vertical edges (I used a measuring cup) to press the crumbs up the wall almost to the top of the sides, and flatten the base.

Beat cream cheese - Use a mixer or beater to beat the cream cheese until smooth - about 30 seconds on medium high,.

Finish batter - Add flour, beat until just combined (10 sec). Add vanilla, sour cream, sugar and lemon zest. Beat until just combined (10 - 15 sec). Add eggs one at a time, beat in between until just combined (10 sec each). Don't over beat, we don't want to aerate the batter.

Bake - Pour into prepared crust. Bake for 55 minutes. The top should be a very light golden brown, not cracked, and near perfectly flat. It should jiggle slightly when you gently shake the pan.

Cool in the oven with the door open 20 cm / 8" (Note 6), then refrigerate for 4 hours+ in the pan.

Remove springform pan sides. Use overhang paper to slide cheesecake off the cake pan. Then slide the cheesecake off the paper.

Serve - Top with berries and dust with icing sugar!