01 - Preheat oven to 325°F (160°C). Grease and line the base of a 9-inch (23 cm) springform pan.
02 - Mix crushed chocolate cookies and melted butter until evenly combined. Press the mixture firmly into the base of the prepared pan. Freeze while assembling the next components.
03 - In a bowl, beat softened butter, brown sugar, and granulated sugar until light and creamy. Mix in milk and vanilla extract. Add heat-treated flour and salt, mixing just until incorporated. Fold in mini chocolate chips. Shape most of the dough into small balls, reserving some for garnish if desired. Refrigerate prepared dough balls.
04 - Beat cream cheese and granulated sugar until completely smooth. Add eggs one at a time, mixing briefly after each addition. Blend in sour cream, vanilla extract, and flour until just combined, avoiding overmixing.
05 - Pour half of the cheesecake filling over the chilled crust. Evenly distribute half of the cookie dough balls over the batter. Pour over the remaining cheesecake filling and gently smooth the surface. Dot the top with additional cookie dough balls if desired.
06 - Place the pan in the oven and bake for 55–65 minutes, until the edges are set but the center remains slightly wobbly. Turn off the oven and crack the oven door. Cool the cheesecake inside for 1 hour without disturbing.
07 - Remove cheesecake from oven and allow to cool fully at room temperature. Refrigerate for at least 4 hours, or preferably overnight, until thoroughly chilled and firm.
08 - Before serving, sprinkle the cheesecake with mini chocolate chips and extra cookie dough balls if desired. Slice with a sharp knife and serve chilled.