01 - Preheat oven to 325°F (160°C). Grease a 9-inch springform pan and line the base with parchment paper.
02 - In a bowl, combine crushed chocolate sandwich cookies with melted butter until evenly moistened. Firmly press the mixture into the bottom of the prepared pan. Freeze while preparing the next layer.
03 - Beat softened butter, brown sugar, and granulated sugar until light and fluffy. Mix in milk and vanilla extract. Add heat-treated flour and salt, stirring until just incorporated. Fold in mini chocolate chips. Shape most of the dough into marble-sized balls, reserving some for topping if desired. Refrigerate until needed.
04 - Beat softened cream cheese with granulated sugar until smooth. Add eggs one at a time, mixing after each addition. Blend in sour cream, vanilla extract, and flour until just combined.
05 - Pour half the cheesecake batter over the crust. Evenly scatter half the cookie dough balls onto the batter. Top with remaining batter and smooth the surface. Arrange extra cookie dough balls on top, if desired.
06 - Bake for 55–65 minutes, until edges are mostly set and the center is slightly jiggly. Turn off oven, crack the door, and let cheesecake cool inside for 1 hour.
07 - Remove pan from oven and allow cheesecake to cool to room temperature. Chill in refrigerator for at least 4 hours or overnight.
08 - Before serving, garnish with mini chocolate chips and reserved cookie dough balls. Slice and serve chilled.