Preheat your oven to 160°C (140°C fan). Wrap the outside of a 23cm springform tin with two layers of foil. You’ll see the foil crinkle slightly as you press it around the base—this is your waterproof layer for the water bath.

Make the crust: In a medium bowl, mix the crushed biscuits, 30g sugar, and melted butter until the mixture looks like wet sand and holds together when you pinch it. Press this firmly into the base of the tin. I use the bottom of a glass to get it even—you’ll hear a satisfying crunch as it compacts. Bake for 10 minutes, then set aside to cool. The crust will smell deeply toasty and will feel firm to the touch.

Start the filling: In a large bowl, beat the cream cheese with an electric mixer on low speed until it’s smooth and looks like thick, glossy yoghurt—no lumps visible. Add the 200g sugar and flour, then beat until just combined. You’ll see the mixture lighten slightly in colour.

Add the flavourings: Mix in the vanilla and lemon zest. The zest will release its oils, and you’ll catch a bright, citrusy scent that lifts the richness.

Add the eggs one at a time: Beat each egg and yolk in on low speed until you see the yellow disappear into the pale cream mixture. Scrape down the sides after each addition. The batter should look thick, smooth, and glossy—like softly whipped cream.

Fold in the double cream: Pour the cream in slowly, folding gently with a spatula. You’re looking for a uniform, velvety texture with no streaks. The batter will feel heavy and luxurious in the bowl.

Assemble and bake: Pour the filling over the cooled crust. Place the springform tin into a large baking tray, then pour boiling water into the tray until it reaches halfway up the sides of the tin. Carefully transfer to the oven and bake for 50–55 minutes. The edges will look set and puffed slightly, but the centre will wobble like a jelly when you gently shake the tin. That wobble is your cue—it will set as it cools.

Cool in the oven: Turn the oven off, crack the door open, and leave the cheesecake inside for 1 hour. You’ll feel the heat gradually release as the cheesecake settles. After that, remove it from the water bath, run a knife around the edge, and let it cool completely on a wire rack. The top will look smooth and pale gold.

Chill overnight: Cover the tin with cling film and refrigerate for at least 6 hours, ideally overnight. When you press the top, it should feel firm but give slightly. The texture will be dense, creamy, and sliceable.