01 - Preheat oven to 325°F. Grease and line the bottom of a 9-inch springform pan.
02 - Combine crushed chocolate sandwich cookies and melted butter until uniform. Press firmly into the bottom of the prepared pan and freeze while assembling other layers.
03 - Cream together softened butter, brown sugar, and granulated sugar until light and aerated. Mix in milk and vanilla extract. Add heat-treated flour and salt, mixing until just incorporated. Fold in mini chocolate chips. Shape most of the dough into small marble-sized balls; reserve some for garnish if desired. Refrigerate until needed.
04 - Blend cream cheese and granulated sugar on medium speed until completely smooth. Incorporate eggs one at a time, mixing after each addition. Add sour cream, vanilla extract, and flour; blend until just smooth.
05 - Pour half the cheesecake batter over chilled crust. Evenly distribute half the cookie dough balls over the batter. Cover with remaining cheesecake batter and smooth the surface. Garnish with reserved cookie dough balls if desired.
06 - Bake at 325°F for 55 to 65 minutes, until edges are set and center wobbles slightly. Turn oven off, crack the door, and allow cheesecake to cool for 1 hour inside.
07 - Remove from oven, let cool to room temperature. Refrigerate for at least 4 hours or overnight to set completely.
08 - Before serving, sprinkle mini chocolate chips and extra cookie dough balls on top. Slice with a sharp knife and serve well chilled.