Place one oven rack in the middle of the oven and one in the bottom third of the oven.
Preheat oven to 300 degrees Fahrenheit.
Spray two baking sheets with non-stick cooking spray; set aside.
In a microwaveable-safe bowl combine the chocolate chips and butter.
Microwave in 20 second intervals, stirring each time until chocolate is melted; set aside.
In another bowl combine flour, baking powder, cocoa, and salt; set aside.
In a large bowl add the sugar, eggs, vanilla and whisk together.
Fold in the chocolate and then the dry ingredients.
Refrigerate the dough for about 10 minutes.
Using ¼ cup measuring cup, drop 6 cupfuls of batter onto each baking sheet, taking care to space evenly.
Bake the cookies for 9 minutes.
Reverse the baking sheets on the racks and bake for 9-10 minutes more.
Cool the cookies completely on the sheets.