01 - Preheat the oven to 325°F. Grease a 9-inch springform pan and line the base with parchment paper.
02 - Combine crushed chocolate sandwich cookies with melted butter until evenly moistened. Press mixture firmly into the base of the prepared pan. Freeze while preparing other layers.
03 - In a mixing bowl, beat softened butter, brown sugar, and granulated sugar together until light and fluffy. Blend in milk and vanilla extract. Add heat-treated flour and salt, mixing just to combine. Fold in mini chocolate chips. Roll most of the dough into marble-sized balls, reserving a portion for optional topping. Refrigerate until use.
04 - Beat cream cheese and granulated sugar together until creamy and smooth. Add eggs one at a time, mixing on low speed after each addition. Blend in sour cream, vanilla extract, and flour just until incorporated.
05 - Pour half the cheesecake batter over the chilled crust. Distribute half of the cookie dough balls over the batter. Pour the remaining cheesecake batter on top and gently smooth the surface. Arrange remaining cookie dough balls on top, if desired.
06 - Bake for 55 to 65 minutes, or until edges are set and the center is slightly wobbly. Turn off the oven, crack the door, and let the cheesecake cool for 1 hour.
07 - Remove the cheesecake from the oven and cool completely at room temperature. Refrigerate for at least 4 hours or overnight for best results. Before serving, sprinkle with mini chocolate chips and reserved cookie dough balls if desired. Slice and serve chilled.