1-First Step: Heat treat the flour and prep the pan Start by heat treating the flour so the cookie dough is safe to eat. Microwave the 1 cup of all-purpose flour for about 90 seconds, then let it cool completely. While that cools, preheat your oven to 350°F. Grease a 9-inch pan and line it with parchment paper, making sure the paper extends about an inch above the sides. That extra paper helps with lifting and also helps prevent cracks as the cheesecake cools.

2-Second Step: Make the crust In a bowl, mix the ground graham crackers, granulated sugar, kosher salt, and melted butter. Stir in the mini chocolate chips last. The mixture should feel like damp sand and hold together when pressed. Pack it tightly into the bottom and sides of the pan. Press firmly so the crust stays neat when sliced later. Bake for 8 minutes, then reduce the oven temperature to 325°F.

3-Third Step: Mix the cookie dough In a separate bowl, mix the room temperature butter and packed light brown sugar by hand until smooth. Add the milk and vanilla extract, then fold in the cooled heat treated flour, kosher salt, and mini chocolate chips. The dough should be soft but thick enough to scoop. Set aside 8 one-tablespoon balls for decoration and refrigerate them while you build the cheesecake. Those chilled pieces will hold their shape better on top.

4-Fourth Step: Build the cheesecake filling Place a large roasting pan on the bottom rack of the oven and bring about 5 cups of water to a boil in a pot. Then beat the cream cheese, sugar, and cornstarch on low speed until smooth. Low speed matters here because it helps keep air bubbles out, which lowers the chance of cracks later. Add the eggs one at a time, then the egg yolk, followed by the vanilla extract and sour cream. Mix only until smooth, then fold in the mini chocolate chips.

5-Fifth Step: Assemble the layers Spread the remaining cookie dough evenly over the baked crust. It may be easiest to flatten small pieces in your hands and place them across the base, then gently smooth them together. Pour the cheesecake batter over the cookie dough layer and spread it evenly with a spatula. The chocolate chip cheesecake filling should cover the cookie dough layer all the way to the edges.

6-Sixth Step: Bake in a water bath Turn off the heat if needed while you pour the boiling water into the roasting pan. Then place the cheesecake on the middle rack above the water bath and bake for 1 hour 20 to 30 minutes. The edges should look puffed, and the center should still jiggle a little. That jiggle test is important. It should move like jello, not look liquid. The slow bake and water bath are two of the biggest secrets to a smooth cheesecake with very few cracks. If the top starts browning too quickly, loosely cover it with foil during baking.

7-Seventh Step: Cool slowly When the baking time is done, leave the cheesecake in the oven, turn off the heat, and crack the oven door for 45 minutes. This gradual cooling helps the cheesecake settle without a sudden temperature drop. After that, remove it from the oven and sprinkle mini chocolate chips over the warm surface so they melt slightly and stick in place. Let it cool at room temperature for 30 minutes, then refrigerate uncovered overnight. That long chill gives the filling time to set fully.

8-Eighth Step: Make the whipped cream and finish Whip the heavy cream, vanilla extract, powdered sugar, and dry milk powder on high speed until stiff peaks form. If you skip the dry milk powder, add the whipped cream just before serving so it stays fluffy. Pipe swirls around the edge of the cheesecake, then top with the reserved cookie dough balls and extra chocolate chips. The final look is playful and bakery-style, and the taste is even better.