Preheat the oven to 350°F (175°C). Line a 9x13 inch baking dish with parchment paper, leaving overhang on the sides for easy removal.
In a mixing bowl, combine flour, baking soda, and salt. Set aside.
In a separate bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy. Add eggs one at a time and mix in the vanilla extract.
Gradually add the flour mixture to the wet ingredients until just combined. Fold in the chocolate chips.
Spread half of the cookie dough evenly in the bottom of the prepared baking dish. Bake for 10 minutes in the preheated oven.
In the meantime, prepare the cheesecake layer. In a mixing bowl, beat the softened cream cheese and sugar until smooth. Add the eggs and vanilla extract, mixing until just combined.
Once the cookie layer has baked for 10 minutes, remove it from the oven and spread the cheesecake mixture over the top.
Crumble the remaining cookie dough over the cheesecake layer.
Prepare the brownie mix according to the package instructions and pour it over the crumbled cookie layer. Use a spatula to spread the brownie batter evenly.
Bake for an additional 30 minutes or until a toothpick inserted into the center comes out clean.
Allow the bars to cool completely in the pan before lifting out using the parchment paper overhang. Cut into 12 squares and serve.