Preheat your oven to 350°F (175°C). Line an 8×8 inch baking dish with parchment paper, leaving an overhang for easy removal.
Combine the graham cracker crumbs and melted butter in a bowl. Press the mixture evenly into the prepared pan to form the crust.
In a mixing bowl, beat the cream cheese and granulated sugar until smooth. Add eggs, vanilla, lemon zest, and lemon juice. Mix until well combined. Pour over the crust.
Drop spoonfuls of raspberry preserves onto the cheesecake layer. Use a knife to gently swirl the raspberry into the filling for a marbled effect.
In a small bowl, combine flour, brown sugar, and cold butter. Use a fork or pastry cutter to create coarse crumbs. Sprinkle evenly over the cheesecake layer.
Bake for 35-40 minutes or until the topping is golden and the center is set. Cool completely in the pan before lifting out and cutting into squares.