01 - Preheat oven to 325°F (160°C). Grease and line the bottom of a 9-inch (23 cm) springform pan.
02 - Combine chocolate cookie crumbs and melted butter in a bowl until evenly moistened. Press mixture firmly into the base of the prepared pan. Freeze while making the next layers.
03 - In a separate bowl, beat together softened butter, brown sugar, and granulated sugar until pale and fluffy. Mix in milk and vanilla. Add heat-treated flour and salt; blend just until incorporated. Fold in mini chocolate chips. Roll most of the dough into marble-sized balls, reserving a portion for topping. Refrigerate until needed.
04 - With an electric mixer, beat cream cheese and granulated sugar until smooth. Incorporate eggs one at a time, mixing thoroughly between each addition. Blend in sour cream, vanilla extract, and flour until mixture is well combined and creamy.
05 - Pour half of the cheesecake batter over the chilled crust. Evenly distribute half of the cookie dough balls over the batter. Cover with the remaining cheesecake filling and gently smooth the surface. Arrange reserved cookie dough balls on top, if desired.
06 - Bake for 55 to 65 minutes, until edges are set but the center remains slightly jiggly. Turn off the oven, crack the oven door, and let the cheesecake cool inside for 1 hour. Remove and let cool to room temperature.
07 - Refrigerate the cheesecake for at least 4 hours or overnight to set completely.
08 - Before serving, sprinkle mini chocolate chips and extra cookie dough balls over the top. Slice and serve cold.