Preheat oven to 350 degrees F. Grease a 9x13-inch pan with cooking spray or line with parchment paper.

Mix together the melted butter and brown sugar. Add the eggs and vanilla and mix.

Add the flour, baking powder, baking soda and salt and mix just until combined.

Stir in the baking chips.

Bake for 24-28 minutes, or until a toothpick inserted in the center comes out clean. Allow to cool for about 20 minutes before cutting.