1.Preheat oven to 350 degrees, spray an 8 x 8 inch square pan, preferably glass pan with cooking spray, set aside.
2.In a large mixing bowl, using a whisk, combine flour, sugars, cocoa powder, baking powder and salt. Whisk to break up clumps.
3.In a small to medium mixing bowl, combine egg, yogurt with milk, and vanilla extract. Use a spoon to combine well.
4.Add wet ingredients into dry and with a rubber spatula, mix until all is combined. Make sure you get all the dry into the wet but try not to over mix the batter. Sprinkle chocolate chips over top of batter.
5.Spread batter in prepared pan. Use the spatula to even out. Bake for about 20 to 25 minutes. A toothpick should come out with moist to dry crumbs. Try not to over bake. Let cool for at least 30 minutes before cutting into squares.