Preheat the oven:

• Preheat your oven to 350°F (175°C). Grease an 8×8-inch or 9×9-inch square baking pan.

Prepare the crust:

• In a medium bowl, combine the graham cracker crumbs, sugar, and melted butter. Mix until the crumbs are evenly coated and the mixture resembles wet sand.
• Press the mixture into the bottom of the prepared pan to form an even crust. Bake for 8-10 minutes, then remove from the oven and set aside to cool.

Prepare the rhubarb layer:

• In a small saucepan, combine the chopped rhubarb, sugar, cornstarch, and water.
• Cook over medium heat, stirring frequently, until the rhubarb softens and the mixture thickens, about 5-7 minutes. Remove from heat and set aside to cool slightly.

Prepare the cheesecake layer:

• In a large mixing bowl, beat the softened cream cheese and sugar together until smooth and creamy.
• Add the vanilla extract and mix until well combined.
• Add the eggs one at a time, beating well after each addition.
• Stir in the sour cream until the mixture is smooth and fully combined.

Assemble the squares:

• Pour the cheesecake batter over the cooled crust, spreading it out evenly.
• Spoon the rhubarb mixture over the top of the cheesecake batter in dollops. Use a knife or skewer to swirl the rhubarb into the cheesecake batter, creating a marbled effect.

Bake the cheesecake squares:

• Bake the assembled squares for 30-35 minutes, or until the center is set and the edges are lightly golden.
• Let the squares cool to room temperature, then refrigerate for at least 2 hours or overnight for best results.

Serve and enjoy:

• Once chilled, cut into squares and serve. Enjoy the sweet and tangy combination of rhubarb and cheesecake in each bite!