Next, add in the flour, cocoa powder, and salt. Mix the dry ingredients into the wet mixture until a brownie batter forms. Fold in the chocolate chips and set aside.

In a separate large mixing bowl, add and mix together the butter, brown and granulated sugars into a smooth mixture, about 2 minutes.

Next, whisk in the egg and vanilla extract. Add and mix the flour, baking soda, and salt into the wet batter just until a soft cookie dough forms, about 1 to 2 minutes. Fold in the chocolate chips.

Preheat oven to 325F. Line the base of an 8 inch springform pan with parchment paper. Set aside.

Add two-thirds of the chocolate chip cookie dough into the prepared baking pan. Use a spatula or hands to pat the cookie dough into an even layer while creating a border, about 1/4 to 1/2 inch high.

Add as many Oreo cookies that can evenly fit over the flattened cookie dough. Gently add and flatten the brownie batter over the Oreo cookies.

With the remaining cookie dough, pat into an even layer and place over the brownie filling. Gently press along the edges of the bottom and top cookie dough layers to seal. Add a few broken up Oreo cookies and additional chocolate chips over the top of the cookie pie.

Place the cookie pie on a baking sheet and transfer to the center rack in preheated oven. Bake cookie pie for 50 to 55 minutes or longer as needed. (For a more gooey cookie pie consistency once set post bake, bake cookie for 45 to 50 minutes.)

Cookie pie is ready when it is fully golden brown with crisp edges. The center of the pie should appear fully baked and not wet or doughy. If cookie pie starts to become overly brown before it is fully baked, tent the baking pan with aluminum foil and continue to bake.

Cool cookie pie at room temperature for about 45 to 60 minutes before cutting into equal slices and serving as is or with whipped cream or ice cream. Enjoy!