In a mixing bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt.
In a separate bowl, mix the sugar, melted butter, eggs, and vanilla. Add the wet ingredients to the dry ingredients and stir until the batter is moistened. Stir in half of the bag of chocolate chips.
Spray a 9x13 baking dish with nonstick cooking spray and spread the brownie batter in an even layer. Sprinkle the remaining chocolate chips evenly over the brownie batter.
Bake the brownies at 350 degrees for 25-35 minutes, until a toothpick inserted comes out almost clean. Remove from the oven and allow the brownies to cool for at least 10 minutes before cutting into squares.