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 in a bowl. Press mixture into the bottom of the prepared pan to form an even layer. Freeze crust while assembling remaining components.
03 - In a mixing bowl, cream softened butter, brown sugar, and granulated sugar until pale and fluffy. Beat in whole milk and vanilla extract. Add heat-treated flour and salt; blend until just combined. Stir in mini chocolate chips. Shape most of the dough into marble-sized balls, reserving a portion for topping. Chill balls until ready to use.
04 - Beat cream cheese and granulated sugar together with an electric mixer until smooth. Add eggs individually, mixing well after each. Blend in sour cream, vanilla extract, and all-purpose flour until batter is just smooth.
05 - Pour half of the cheesecake filling over the chilled crust. Evenly scatter half of the cookie dough balls over the batter. Cover with the remaining cheesecake filling, smoothing the surface. Distribute reserved cookie dough balls on top as desired.
06 - Bake for 55 to 65 minutes, until edges are set and the center remains slightly wobbly. Turn off the oven, crack the door open, and allow cheesecake to cool inside for 1 hour.
07 - Remove from the oven and let cool completely at room temperature. Refrigerate for at least 4 hours or overnight to ensure proper setting.
08 - Before serving, sprinkle cheesecake with mini chocolate chips and remaining cookie dough balls, if using. Slice and serve chilled.