Preheat oven to 350 and grease a 9x9 baking dish with nonstick cooking spray. Set aside.
Beat together butter, white and brown sugar until fluffy, about 5 minutes. Add eggs and vanilla and beat well.
In a small bowl, combine flour, baking powder and salt and add to mixing bowl. Beat just until combined. Add ½ cup candies, chocolate chips and 8 crushed cookies. Fold into batter. Spoon batter into prepared pan and spread evenly.
Bake for 25 minutes. Remove from oven and crush additional 2 cookies and sprinkle on top. gently press into dough. Sprinkle with remaining candies and gently press into top. Cool completely before cutting.