1. Prepare the Crust
Preheat oven to 325 °F (163 °C). Grease a 9-inch springform pan and line the bottom with parchment.
Mix graham crumbs, melted butter, and sugar until evenly moistened.
Press firmly into the bottom (and slightly up the sides) of the pan.
Bake for 8–10 minutes, then let cool slightly.

2. Make the Raspberry Swirl
In a small saucepan, combine raspberries, sugar, and lemon juice.
Cook over medium heat for 2–3 minutes until raspberries release juice.
Optional: add cornstarch slurry and cook 1–2 minutes more until slightly thickened.
Strain through a fine sieve to remove seeds if you prefer a smooth swirl.
Let cool completely.

3. Make the Lemon Cheesecake Filling
Beat cream cheese until smooth. Add sugar and flour; mix until creamy.
Add sour cream, lemon juice, and zest; beat until silky.
Add eggs and yolks one at a time on low speed, just until incorporated. Avoid over-mixing.

4. Assemble & Bake
Pour the lemon filling over the cooled crust.
Dollop spoonfuls of raspberry sauce on top and gently swirl with a knife or toothpick.
Bake for 50–60 minutes, or until edges are set and the centre slightly jiggles.
Turn off oven, crack door open, and cool inside for 30 minutes.
Then remove and cool completely at room temperature before refrigerating for at least 4 hours (preferably overnight).

5. Slice & Serve
Once fully chilled, run a knife around the pan edge, release the springform ring, and transfer to a serving plate.
Slice with a hot, clean knife (wipe between cuts).
Garnish with fresh raspberries, lemon zest, or a light dusting of powdered sugar.