Preheat the oven to 150℃
Lightly grease an 18-20cm springform tin with butter.
Use a food processor to blitz the digestive biscuits until they resemble fine crumbs. Alternatively, you can put these into a sandwich bag and smash them with a rolling pin.
Melt the butter, then add it to the digestives, mix until it is well combined and resembles wet sand.
Place the mix into the springform tin, press down firmly. Place it in the fridge whilst you get the cheesecake filling ready.
Use a whisk to beat the cream cheese until smooth. Add the flour and beat until well combined.
Add the vanilla, lemon zest, sugar, and soured cream. Whisk until it is just combined.
Add the eggs one at a time and beat to combine. Do not over beat as this will aerate the mix.
Pour the mix into the tin.
Bake for 50 minutes. The top should be slightly golden, and it should have a slight wobble.
Turn the oven off but leave the cheesecake in the oven for an hour with the oven door partly open.
Once cool, place the cheesecake in the fridge for at least four hours, but ideally overnight.
Unclip the sides and cut the cheesecake into portions. Serve with berries and a dusting of icing sugar.