01 - Preheat the oven to 325°F (160°C). Line an 8-inch square baking pan with parchment paper, leaving an overhang on two sides.
02 - Combine graham cracker crumbs, sugar, melted butter, and salt in a medium bowl. Press firmly into the bottom of the prepared pan. Bake for 10 minutes and allow to cool slightly.
03 - In a small saucepan over medium heat, combine raspberries, sugar, and lemon juice. Cook for 3 to 5 minutes, stirring and mashing until thickened. Strain through a fine sieve to remove seeds and cool.
04 - Beat cream cheese and sugar in a large bowl until smooth. Add eggs one at a time, mixing thoroughly after each addition. Stir in vanilla extract, lemon zest, lemon juice, and sour cream until fully combined.
05 - Pour the cheesecake batter evenly over the cooled crust and smooth the surface.
06 - Drop spoonfuls of raspberry sauce on top of the cheesecake batter. Use a toothpick or knife to gently swirl for a marbled effect.
07 - Bake for 30 to 35 minutes, until the edges are set and the center remains slightly jiggly.
08 - Allow to cool to room temperature, then refrigerate for at least 2 hours before cutting into 16 squares.