1-First, preheat your oven to 325°F (163°C) and line a 9×13-inch pan with parchment paper for easy removal later.

2-In a bowl, combine 1 1/2 cups graham cracker crumbs, 1/3 cup melted butter, and 2 tablespoons sugar until it resembles wet sand; press this mixture evenly into the prepared pan to form the crust.

3-Bake the crust for about 10 minutes, then remove it from the oven and let it cool while you prepare the filling.

4-In a large mixing bowl, beat 24 ounces of softened cream cheese with 3/4 cup sugar until smooth and creamy; add 3 large eggs one at a time, mixing well after each.

5-Incorporate 3/4 cup sour cream, 1 teaspoon vanilla extract, 1/2 teaspoon salt, and a squeeze of fresh lemon juice into the mixture until fully blended.

6-Divide 1 1/3 cups of the smooth filling into two small bowls and color one with red gel food coloring and the other with blue gel food coloring.

7-Pour the plain filling over the cooled crust, then add alternating lines of the red and blue fillings on top; use a knife or chopstick to swirl them into a marbled pattern.

8-Bake the bars at 325°F (163°C) for 50-55 minutes with a water-filled pan on the lower rack for even cooking.

9-Turn off the oven and leave the bars inside with the door open for 1 hour, then refrigerate overnight to set fully.

10-Finally, cut the bars into squares before serving for a festive presentation.