01 - Preheat oven to 325°F (160°C). Grease and line the bottom of a 9-inch springform pan.
02 - Combine crushed chocolate sandwich cookies and melted butter in a bowl. Mix until the crumbs are fully moistened. Press evenly and firmly into the bottom of the prepared pan. Place pan in the freezer while preparing the remaining components.
03 - In a separate bowl, cream together softened butter, brown sugar, and granulated sugar until light and fluffy. Incorporate milk and vanilla extract. Add heat-treated flour and salt. Stir until a soft dough forms, then fold in mini chocolate chips. Shape most of the dough into small marble-sized balls, reserving some for topping if desired. Refrigerate until further use.
04 - In a large bowl, beat softened cream cheese with granulated sugar until completely smooth. Add eggs one at a time, blending thoroughly after each addition. Gently mix in sour cream, vanilla extract, and flour until just incorporated.
05 - Pour half of the cheesecake batter over the chilled crust. Scatter half the prepared cookie dough balls evenly over the batter. Add the remaining batter, smoothing the surface gently with a spatula. Arrange reserved cookie dough balls on top if desired.
06 - Bake in preheated oven for 55 to 65 minutes, or until the edges are set and the center slightly wobbles. Switch off the oven, crack the door, and allow the cheesecake to cool inside for 1 hour.
07 - Once cooled to room temperature, refrigerate the cheesecake for at least 4 hours or overnight for optimal texture and flavor.
08 - Before serving, top with additional mini chocolate chips and reserved cookie dough balls if desired. Slice with a sharp knife and serve well chilled.