Preheat your oven to 350°F (175°C). Prepare your 7-inch springform pan by lining the bottom with parchment paper and wrapping the exterior in aluminum foil to prevent any water from seeping in during baking.

In a bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Press the mixture into the bottom of the prepared pan, creating a compact layer.

In another bowl, mix together all-purpose flour, brown sugar, granulated sugar, cornstarch, and ground cinnamon. Stir in melted butter until crumbly; set aside.

In a mixing bowl, use an electric mixer to beat together softened cream cheese and superfine granulated sugar until smooth and creamy. Add sour cream and vanilla extract, mixing until fully incorporated.

Add in the large eggs, one at a time, beating just until blended.

Pour the cheesecake filling onto the graham cracker crust in the pan. Gently dollop strawberry preserves over the top and swirl with a knife for a marbled effect. Sprinkle the crumble mixture evenly over the top.

Place the springform pan on a larger baking dish filled with hot water, creating a water bath. Bake for 85-90 minutes or until the center is set (it should slightly jiggle when shaken).

After baking, remove the cheesecake from the oven and let it cool to room temperature. Refrigerate for at least 4 hours or overnight for best results.

Before serving, whisk together confectioners' sugar and whole milk until smooth and drizzle over the cheesecake.