Crunchy, chewy, creamy, Monster Cookie Chocolate Cheesecake Bars are a dessert dream come true!
Preheat the oven to 350°F. Line a 9x13 pan with parchment paper or line with foil and grease with butter.
FOR THE COOKIE CRUST: Beat the butter and both sugars together until fluffy. Add the peanut butter, eggs, and vanilla, and beat until smooth. In a separate bowl, stir together the flour, salt, baking soda, and oats. Slowly add the dry ingredients to the butter mixture, and beat until combined. Add the milk and beat again.
Stir in the chocolate chips and the M&M's candies by hand, reserve about 2 tablespoons of M&M's for topping. Press half the cookie dough into the bottom of the prepared pan. Set aside the pan and the remaining cookie dough.
FOR THE CHEESECAKE: Beat the cream cheese until creamy. Add the sugar and beat until smooth. Add the chocolate and beat until creamy again. Add the eggs, beating well to make sure they are well incorporated, but do not overbeat the batter.
Spread the cheesecake batter over the layer of cookie dough already in the pan. Drop the remaining cookie batter by scoops or spoonfuls over the cheesecake layer. Sprinkle the remaining M&M's on top.
Bake for 35 minutes. Remove the pan from the oven and place it on a wire rack. Let cool for 1 hour, then refrigerate for at least 4 hours, or until completely chilled. Cut into 24-48 bars before serving. Enjoy!
To melt the chocolate (for the cheesecake) in the microwave, place it in a glass bowl and heat for 1 minute at 50% power, stir, and heat an additional 30 seconds at 50% power ONLY if needed. When the chips are mostly melted, remove from the microwave and stir until smooth and fully melted.