Step 1: Prepare the Crust

1. Preheat your oven to 325°F (160°C).
2. In a bowl, mix the crushed graham crackers, sugar, and melted butter until well combined.
3. Press the mixture firmly into the bottom of a greased 9-inch springform pan.
4. Bake for 10 minutes, then let it cool while you prepare the filling.

Step 2: Make the Raspberry Swirl

1. In a small saucepan, combine raspberries, sugar, cornstarch, and water.
2. Cook over medium heat, stirring, until the raspberries break down and the sauce thickens (about 5 minutes).
3. Strain the mixture through a fine mesh sieve to remove the seeds. Set aside to cool.

Step 3: Prepare the Cheesecake Filling

1. In a large bowl, beat the cream cheese and sugar until smooth and fluffy.
2. Add eggs one at a time, mixing just until combined.
3. Mix in the lemon juice, lemon zest, vanilla extract, and sour cream. Do not overmix to avoid air bubbles.

Step 4: Assemble the Cheesecake

1. Pour the cheesecake batter over the cooled crust.
2. Spoon small dollops of the raspberry sauce on top.
3. Use a toothpick or skewer to gently swirl the raspberry sauce into the cheesecake batter.

Step 5: Bake the Cheesecake

1. Wrap the outside of the springform pan with foil and place it in a large baking dish.
2. Fill the baking dish with about 1 inch of hot water (water bath method to prevent cracks).
3. Bake at 325°F (160°C) for 50-60 minutes, or until the center is slightly jiggly but set around the edges.

Step 6: Cool & Chill

1. Turn off the oven and crack the door open. Let the cheesecake cool for 1 hour inside.
2. Transfer to the fridge and chill for at least 4 hours, preferably overnight.

Step 7: Serve & Enjoy!

1. Remove the cheesecake from the springform pan.
2. Garnish with fresh raspberries, lemon zest, or whipped cream if desired.
3. Slice, serve, and enjoy the creamy, citrusy goodness!