1. Prepare the Raspberry Swirl:

1. In a small saucepan, combine raspberries, sugar, and lemon juice.
2. Cook over medium heat, stirring and mashing berries, until thickened (about 5 minutes).
3. Strain through a fine mesh sieve to remove seeds, if desired. Let cool.

2. Make the Crust:

1. Preheat oven to 325°F (163°C). Line an 8-inch (20cm) square baking pan with parchment paper, leaving overhang.
2. Mix graham cracker crumbs, sugar, melted butter, and salt until combined.
3. Press mixture firmly into the bottom of the prepared pan.
4. Bake for 8–10 minutes, then let cool slightly.

3. Make the Cheesecake Filling:

1. Beat cream cheese and sugar until smooth and creamy.
2. Add eggs one at a time, mixing well after each.
3. Mix in vanilla and sour cream until just combined.

4. Assemble and Bake:

1. Pour cheesecake filling over the cooled crust and smooth the top.
2. Drop spoonfuls of raspberry sauce over the cheesecake layer.
3. Use a knife or toothpick to gently swirl the raspberry sauce into the cheesecake.
4. Bake for 35–40 minutes, or until the center is set but still slightly jiggly.
5. Cool to room temperature, then refrigerate for at least 3 hours (overnight is best).

5. Serve:

1. Lift bars out of the pan using parchment paper.
2. Slice into squares and enjoy!