01 - Preheat oven to 325°F. Lightly grease and line the base of a 9-inch springform pan.
02 - Combine crushed chocolate sandwich cookies with melted butter in a bowl. Press the mixture firmly and evenly into the bottom of the prepared pan. Freeze the crust while preparing remaining components.
03 - In a mixing bowl, beat softened butter with brown and granulated sugars until light and fluffy. Mix in milk and vanilla extract. Add heat-treated flour and salt, stirring just until combined. Fold in mini chocolate chips. Roll most of the dough into marble-sized balls, reserving some for topping. Refrigerate dough balls until needed.
04 - Using an electric mixer, blend softened cream cheese and granulated sugar until smooth. Beat in eggs one at a time, mixing briefly after each addition. Fold in sour cream, vanilla extract, and all-purpose flour just until incorporated.
05 - Pour half of the cheesecake batter onto the chilled crust. Distribute half the cookie dough balls over the batter. Cover with remaining cheesecake batter and smooth the surface. Arrange reserved cookie dough balls on top for visual appeal if desired.
06 - Bake for 55 to 65 minutes, until edges are set and center is slightly jiggly. Turn off the oven and prop the door ajar. Let cheesecake cool inside oven for 1 hour.
07 - Remove from oven and cool completely on a rack at room temperature. Refrigerate covered for at least 4 hours or overnight to ensure full firmness.
08 - Before serving, scatter mini chocolate chips and reserved cookie dough balls on top. Slice with a sharp knife, cleaning blade between cuts. Serve well-chilled.