Preheat the oven to 325 degrees Fahrenheit. Line a 9x9-inch glass baking dish with parchment paper, leaving an inch or two hanging off the sides. Set aside.
Now, make the crust. Combine graham crackers, peanut butter and butter in a food processor and pulse until crumbly yet sticky. Press this mixture into the prepared baking dish and bake in the 325 degree oven for 10 minutes.
While crust is baking, prepare the cheesecake filling. In the bowl of a stand mixer, combine the cream cheeses, eggs, sugar, flour, vanilla and sour cream.
Remove crust from oven and increase oven temperature to 350 degrees Fahrenheit. Pour cheesecake batter over the graham cracker crust.
Place jam or jelly in a small ramekin and microwave for 20 seconds. Scoop dollops of jam evenly over top of cheesecake batter, then drag a knife or toothpick through the dollops to create a swirl pattern.
Bake cheesecake in 350 degree oven for 30-35 minutes, or until the edges begin to turn golden and the middle is still slightly jiggly. Let rest, out of the oven, until cool enough to touch and then transfer to the refrigerator. Refrigerate for at least a few hours or overnight.
Remove cheesecake from the refrigerator and, using the overhanging parchment paper, pull bars out of the baking dish and onto a cutting board. Use a sharp knife to cut the cheesecake into 12 bars. Enjoy!