Preheat the oven to 350F degrees. Line cookie sheets with parchment paper or baking mats.
In a medium bowl whisk together the flour, cocoa, baking powder and salt until there's no lumps. Set aside.
Chop the chocolate into very fine pieces and place in a heatproof bowl with the butter. Microwave on medium power for 45-second intervals. Stir in between each interval until smooth. Set aside.
In a large bowl beat the eggs and sugar until pale in color (about 1-2 minutes).
Mix the melted chocolate mixture into the egg mixture until its even in color.
Gently stir the flour mixture into the batter. If there's lumps, use an electric mixer on low speed until it's smooth. The batter will be glossy and sticky.
Sir in the chocolate chips.
Lightly spray a cookie scoop (or tablespoon) with non-stick cooking spray. Scoop out about 1 - 1.5 tablespoons of dough and drop onto the lined cookie sheet. Ensure that each dough balls is about 2 inches apart.
Bake 1 sheet at a time on the middle rack in the preheated oven for 9-11 minutes, or until the tops look set. They should be crinkly and shiny.
Cool the cookies on the cookie sheet, then transfer to a wire rack using a metal spatula.