First Step: PREPARE THE CRUST

1. Make the Crust: Begin by preparing the graham cracker crust. In a medium bowl, combine the graham cracker crumbs, sugar, and melted butter. Stir until the mixture is well combined and resembles wet sand.
2. Press the Crust: Transfer the crumb mixture to a 9×13-inch baking dish and press it into an even layer. Use the back of a spoon or your fingers to compact the crumbs firmly to form a solid base.
3. Bake the Crust: Preheat your oven to 325°F (163°C). Bake the crust for about 10 minutes, until it’s lightly golden and fragrant. Once baked, remove from the oven and set aside to cool while you prepare the cheesecake filling.

Second Step: PREPARE THE CHEESECAKE FILLING

1. Prepare the Cream Cheese: In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth and creamy. Scrape down the sides of the bowl to ensure there are no lumps.
2. Add Sour Cream and Sugar: Add the sour cream and sugar to the cream cheese and beat until the mixture is well combined and smooth.
3. Incorporate the Eggs: Add the eggs, one at a time, beating well after each addition. Scrape down the sides of the bowl to ensure everything is fully incorporated.
4. Add Flour and Vanilla: Mix in the flour and vanilla extract. The flour helps to stabilize the cheesecake filling and ensures a smooth texture during baking.
5. Swirl in Nutella: Warm the Nutella slightly in the microwave for about 15-20 seconds to make it easier to swirl. Add ½ cup of Nutella to the cheesecake batter and gently fold it in. Be careful not to overmix; you want to create a marbled effect rather than fully blending the Nutella into the batter.

Third Step: ASSEMBLE AND BAKE THE CHEESECAKE BARS

1. Layer the Cheesecake: Pour the cheesecake filling over the prepared graham cracker crust. Smooth the top with a spatula to ensure an even layer.
2. Swirl the Nutella: Drop spoonfuls of the remaining Nutella over the cheesecake filling. Using a knife or a skewer, gently swirl the Nutella into the filling to create a marbled pattern. Be careful not to overmix—the swirls should be visible, creating a beautiful design on top.
3. Bake the Cheesecake Bars: Place the dish in the preheated oven and bake at 325°F (163°C) for about 40-45 minutes, or until the edges are set and the center has a slight jiggle. The cheesecake should still be a little soft in the center but firm enough to hold its shape.
4. Cool the Cheesecake: Once the bars are done, turn off the oven and allow the cheesecake to cool in the oven with the door slightly ajar for about 1 hour. This gradual cooling helps prevent cracks from forming.
5. Chill the Cheesecake: After the cheesecake has cooled to room temperature, transfer it to the refrigerator and chill for at least 3 hours or preferably overnight. This helps the cheesecake set and makes it easier to slice into bars.

Final Step: GARNISH AND SERVE

1. Garnish: Just before serving, garnish the cheesecake bars with chopped hazelnuts for added texture and a burst of nutty flavor. You can also drizzle a little extra Nutella on top for an extra indulgent touch.
2. Slice and Serve: Slice the chilled cheesecake into bars. Use a sharp knife to ensure clean cuts. Serve chilled and enjoy the creamy, Nutella-infused goodness!