Preheat the oven to 350° F.
Line a baking sheet with parchment paper and set aside.
In a bowl, weigh out the dry ingredients (flour, baking powder, cocoa powder, and salt) and whisk it all together, then set it aside.
In a microwave safe bowl, add the chopped chocolate and cubed butter and melt in 30 second increments, making sure to stir between each increment. Then set it aside to cool, at least 10 minutes.
In a medium bowl, add brown sugar, granulated sugar and the room temperature eggs and beat with a hand mixer (or stand mixer) for 5 minutes on HIGH speed until the egg and sugar mixture become a pale color, fluffy, and ribbony. It may take longer than 5 minutes, depending on your mixer.
Slowly add the slightly cooled chocolate to the egg/sugar mixture and beat just until combined.
Fold in the dry ingredients using a spatula and do not over mix. Just fold in until the dry ingredients are combined.
Using a medium (3 tbsp) cookie scoop, scoop the cookie dough onto the baking sheet, and immediately bake for 8 minutes. I like mine fudgy in the center so 8 minutes is perfect.
When baking is complete, remove from oven and let sit for a couple minutes before transferring to a cooling rack. Store in an airtight container.