01 - Preheat oven to 325°F (160°C). Grease a 9-inch springform pan and line the bottom with parchment paper.
02 - In a medium bowl, combine crushed chocolate sandwich cookies and melted butter until evenly moist. Press the mixture firmly into the bottom of the prepared pan to form a compact layer. Transfer to the freezer while proceeding with the next steps.
03 - In a bowl, beat softened butter, brown sugar, and granulated sugar until light and creamy. Mix in milk and vanilla. Add heat-treated flour and salt, mixing just until a soft dough forms. Fold in mini chocolate chips. Shape most of the dough into marble-sized balls for the cheesecake, reserving some for optional topping. Chill until needed.
04 - In a large bowl, beat cream cheese and granulated sugar on medium speed until smooth. Add eggs one at a time, mixing briefly after each, then blend in sour cream, vanilla, and flour just until combined.
05 - Pour half the cheesecake mixture over the chilled crust. Scatter half of the prepared cookie dough balls evenly across the surface. Cover with remaining cheesecake mixture, smoothing the top, and arrange the rest of the cookie dough balls over the batter for a decorative finish.
06 - Bake in preheated oven for 55 to 65 minutes, or until edges are set and the center jiggles slightly. Turn off the oven, crack the door, and let the cheesecake cool inside for 1 hour.
07 - Transfer cheesecake to a wire rack and let cool completely at room temperature. Refrigerate for at least 4 hours or overnight to fully set.
08 - Before serving, top with mini chocolate chips and extra cookie dough balls if desired. Slice with a sharp, clean knife and enjoy chilled.