18.4ouncepackage brownie mix (I used Pillsbury Chocolate Fudge)
Preheat oven to 350 degrees F. Spray a 13- x 9-inch baking dish with non-stick cooking spray.
For the Chocolate Chip Cookie Layer
Using an electric mixer, beat softened butter, brown sugar, white sugar, and vanilla extract together in a large bowl until creamy. Add eggs and continue to beat for another two minutes or until light and creamy.
In a medium mixing bowl combine flour, salt, and baking soda. Use a spoon to add flour mixture into butter mixture in increments, stirring until dough is combined. Stir chocolate chips into dough. Spread dough into the bottom of the prepared baking dish and use your hands to press it into an even layer.
Place the Halloween Oreo Cookies in rows over the dough.
For the Brownie Layer
Combine brownie mix, oil, water and eggs in a large mixing bowl. Stir until well combined.
Pour the prepared brownie batter over the Halloween Oreos.
Bake for 40 to 45 minutes or until toothpick inserted in the bars comes out clean. Allow to cool completely in pan and then cut into squares and serve.
Store bars in an airtight container.
This recipe will yield 48 small bars or 24 larger bars.