Lightly grease a 9-inch x 9-inch baking pan and line with parchment paper.
Pre-heat the oven to 350°F (325°F for glass bake ware)
In a medium bowl, cream the butter and brown sugar until light and fluffy.
Add the egg and vanilla extract; beat well.
In a small bowl, sift together the flour, baking powder and baking soda.
Add dry ingredients to the creamed mixture; fold to combine well.
Fold in the chocolate chips.
Spread in the prepared baking pan; place in pre-heated and bake for 15 minutes.
Remove from oven and immediately sprinkle with the Oreo pieces and caramel candies; do not turn off the oven.
Pour the brownie batter evenly over everything in the pan.