Preheat your oven to 350°F (175°C). In a mixing bowl, combine graham cracker crumbs, sugar, and melted butter until the mixture resembles wet sand. Firmly press this into the bottom of a springform pan. Bake for 10 minutes until lightly golden, then let it cool completely.

In a large mixing bowl, beat the softened cream cheese with a hand mixer until creamy and smooth. Gradually add in sugar and vanilla extract, mixing well until combined. Incorporate eggs one at a time, followed by lemon juice and zest, and finally the sour cream. Blend until everything is incorporated.

In a saucepan over medium heat, combine fresh raspberries, sugar, lemon juice, cornstarch, and water. Stir gently while cooking. Once thickened, remove from heat and allow to cool slightly before incorporating into your cheesecake.

Pour the cheesecake filling over your cooled crust, spreading it evenly. Dollop raspberry sauce over the filling and gently swirl through the batter. Bake for 60-70 minutes until the center appears slightly jiggly but set around the edges.

Turn off the oven and crack open the door slightly to allow the cheesecake to cool slowly for about an hour. Transfer to the refrigerator and chill for at least 4 hours, or overnight.