Preheat the oven to 350°F. Line a 13x9 inch metal baking pan with heavy duty foil. Spray liberally with baking spray.Set aside.
To make the cheesecake layer: Using an electric hand mixer or stand mixer whip together the cream cheese, 2 large eggs, 1/2 cup granulated sugar and 1 tsp vanilla. Beat on medium-high for 2 minutes or until completely smooth. Set aside.
To make the cookie layer: In a large mixing bowl beat together the softened butter, 3/4 cup granulated sugar, 3/4 cup brown sugar and 1 tsp vanilla until fully combined. Add 2 large eggs, one at a time. Beat well after each addition.
Sift together the flour, baking soda and salt. Lower the speed of the mixer and add gradually to the creamed butter. Stop and scrape the sides of the bowl periodically. (A whisk works perfectly to sift the dry ingredients)
Mix in 2 cups chocolate chips by hand until equally distributed in the cookie dough.
To assemble: Spread 2/3 of the cookie dough in the pan. Top with cheesecake mixture, spread evenly.
Use a teaspoon to dollop remaining cookie dough on top. Gently spread over the cheesecake. It may not be completely covered. Sprinkle with remaining 1/2 cup chocolate chips.
Bake for 30 minutes. Check for browning and lay aluminum foil on top. Bake for another 20-30 minutes or until a toothpick inserted into the center comes back clean.
Cool in the pan on a baking rack. Once cooled, lift from pan using aluminum foil, then cut into 36 equal pieces.
Store leftovers chilled.