Prep the pan and oven. Heat the oven to 350°F (175°C). Line an 8x8 pan with parchment, leaving overhang for easy lifting.
Make the cookie dough.
Beat butter, granulated sugar, and brown sugar until creamy. Mix in the egg and vanilla. Add flour, baking soda, and salt.
Stir until just combined, then fold in chocolate chips.
Form the crust. Press about 2/3 of the dough evenly into the lined pan. Reserve the rest for topping.
Make the cheesecake layer.
Beat cream cheese until smooth. Add sugar, sour cream, egg, vanilla, and a pinch of salt. Mix until creamy with no lumps.
Assemble.
Pour the cheesecake batter over the crust and smooth the top. Crumble or flatten small pieces of the remaining cookie dough and scatter them evenly over the cheesecake layer.
Bake. Bake for 28–34 minutes, until the cookie topping is golden and the center looks set but slightly jiggly.
Cool and chill.
Let the pan cool to room temperature. Refrigerate for at least 3 hours (overnight is best) before slicing.
Slice and serve. Lift out with the parchment, slice into bars, and enjoy chilled or slightly cool.