Preheat the oven and spray a 9x13 baking dish with pam baking spray
Using a hand mixer, beat together the butter, brown sugar, sugar, egg and vanilla until combined
In a large bowl, whisk together the flour, baking soda, baking powder and salt until combined
Gradually whisk in the dry ingredients into the wet until combined
Fold in ¾ cup each of M&M’s and chocolate chips
Fold in 1 ½ C chopped oreos into the batter
Press the dough into the baking dish
Sprinkle the remaining M&M’ss, chocolate chips and chopped oreos on top
Bake in the oven for 20-25 minutes or until lightly brown
Remove and allow to cool completely before cutting into bars