1. Preparing the Crust

1. Preheat oven to 325°F (165°C).
2. In a bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Mix until the mixture is evenly coated.
3. Press the crumb mixture into the base of a springform pan to form a firm crust. Bake for 10 minutes, then set aside to cool.

2. Making the Cheesecake Batter

1. In a large bowl, beat cream cheese with granulated sugar until smooth.
2. Add sour cream, vanilla bean paste, and eggs, one at a time, mixing after each addition.
3. Mix in the cornstarch-water mixture for a smooth texture.
4. Divide the batter into two equal parts.
5. In one half, add blue gel food coloring and mix until you achieve the desired blue shade.

3. Creating the Blue Swirl

1. Pour the white cheesecake batter into the prepared crust, then swirl in the blue-colored batter using a toothpick or knife.
2. Gently swirl to create a beautiful marble effect.

4. Assembling and Baking

1. Bake the cheesecake at 325°F (165°C) for about 55-60 minutes, or until the center is set and slightly jiggly.
2. Let the cheesecake cool in the oven with the door slightly ajar for 1 hour, then transfer to the fridge and chill for at least 4 hours (overnight is best).