01 - Preheat oven to 325°F (160°C). Grease and line the base of a 9-inch springform pan with parchment paper.
02 - Combine crushed chocolate sandwich cookies with melted butter until uniformly moist. Press mixture firmly into the bottom of the prepared pan, creating an even layer. Freeze while preparing the next components.
03 - In a bowl, beat softened butter, brown sugar, and granulated sugar with an electric mixer until light and fluffy. Blend in milk and vanilla. Add heat-treated flour and salt, mixing until just combined. Fold in mini chocolate chips. Roll most of the dough into marble-sized balls, reserving some for decoration. Refrigerate until needed.
04 - In a separate bowl, beat cream cheese and granulated sugar until creamy and smooth. Add eggs one at a time, mixing after each addition. Blend in sour cream, vanilla extract, and flour until just incorporated, avoiding over-mixing.
05 - Pour half of the cheesecake filling over the chilled crust. Distribute half of the chilled cookie dough balls over the filling. Cover with the remaining cheesecake batter and smooth the surface. Top with reserved cookie dough balls if desired.
06 - Bake for 55 to 65 minutes, or until the edges are set and the center is slightly wobbly. Turn off the oven, crack open the oven door, and cool for 1 hour inside.
07 - Remove from oven. Let cool completely at room temperature, then refrigerate at least 4 hours or preferably overnight for best texture.
08 - When ready to serve, sprinkle mini chocolate chips and reserved cookie dough balls over the top. Slice with a sharp knife and serve chilled.