Preheat your oven to 325°F (160°C). This ensures that the cheesecake bakes evenly.

In a mixing bowl, combine the graham cracker crumbs, granulated sugar, and melted butter. Mix until the crumbs are evenly coated and the mixture resembles wet sand.

Press the crumb mixture firmly into the bottom of a 9x9 inch baking pan lined with parchment paper. Use the back of a measuring cup to pack it tightly. This creates a solid base for the cheesecake.

Bake the crust in the preheated oven for 10 minutes, then remove and let it cool while you prepare the filling.

In a large mixing bowl, beat the softened cream cheese with an electric mixer on medium speed until smooth and creamy, about 2-3 minutes.

Add the granulated sugar and vanilla extract. Beat until well combined, scraping down the sides of the bowl as necessary.

Add the eggs one at a time, mixing on low speed after each addition until just combined. Overmixing can lead to cracks in your cheesecake.

Gently fold in the sour cream and rainbow sprinkles using a spatula. This adds creaminess and fun color to your cheesecake.

Pour the cheesecake filling over the cooled crust, spreading it evenly.

Bake the cheesecake in the oven for 30-35 minutes, or until the edges are set and the center is slightly jiggly. The residual heat will continue to cook the center as it cools.

Turn off the oven and crack the door open, allowing the cheesecake to cool in the oven for an additional hour. This helps prevent cracks.

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

Once chilled, lift the cheesecake out of the pan using the parchment paper. Cut into bars and top with additional rainbow sprinkles.

Serve chilled and enjoy your delicious Funfetti Cheesecake Bars!