Step 1: Prepare the Crust

1. Preheat the oven to 325°F (163°C).
2. In a medium bowl, mix graham cracker crumbs, sugar, and melted butter until combined.
3. Press the mixture firmly into the bottom of a greased 9×9-inch baking pan.
4. Bake for 8 minutes, then set aside to cool slightly.

Step 2: Make the Cheesecake Layer

1. In a large mixing bowl, beat cream cheese, sugar, and vanilla extract until smooth and creamy.
2. Add the egg and mix just until combined (avoid overmixing).
3. Pour the cheesecake mixture over the slightly cooled crust and spread evenly.

Step 3: Prepare the Cookie Dough Topping

1. In another bowl, cream together butter, brown sugar, and granulated sugar until light and fluffy.
2. Mix in vanilla extract.
3. Gradually add flour and mix until combined.
4. Fold in mini chocolate chips.
5. Drop spoonfuls of the cookie dough mixture over the cheesecake layer, then gently spread it out.

Step 4: Bake & Chill

1. Bake for 30-35 minutes or until the edges are set and the cookie dough topping is lightly golden.
2. Let cool at room temperature, then refrigerate for at least 2 hours before slicing.