Preheat oven to 350℉ (180℃)
Prepare 2 baking sheets by lining with parchment paper or silicone baking mats.
In a medium bowl, whisk together flour, cocoa powder, salt and baking powder. Set aside for later. Note - sift the flour and cocoa powder if it appears lumpy.
1 ¼ Cup All Purpose Flour, ½ Cup Dutch Processed Cocoa Powder, 1 teaspoon Salt, 2 teaspoons Baking Powder
Place chocolate in a microwave safe bowl.
1 Cup Chocolate, bittersweet
Heat the chocolate in the microwave at 50% power for 30 seconds. Take it out and stir the chocolate really well. Keep heating it in 30-second intervals at 50% power, stirring each time, until the chocolate is completely melted. See notes below for an alternative way to melt chocolate without using a microwave.1
Using a stand mixer with the paddle attachment, begin mixing butter and granulated sugar together until light and fluffy (2 - 4 minutes on medium speed). Scrape the bowl as needed. The mixture should appear light and smooth.
½ Cup Unsalted Butter, room temperature, 1 ¼ Cup Granulated Sugar
Add eggs one at a time to bowl with butter and sugar. Mix on medium speed between each addition. Scrape sides of bowl as needed.
2 Large Eggs
Add melted chocolate to mixing bowl. Mix on medium speed, scraping the side of the bowl occasionally, until the chocolate is well combined.
Add milk to the mixing bowl. Mix on low speed until combined.
⅓ Cup Whole Milk
Add flour mixture and mix on low speed until combined.
Scoop cookie dough onto the parchment-lined baking sheets using a cookie scooper (approximately 2 tablespoons per cookie). Leave approximately 2 inches of space between each cookie.
Bake cookies for 8 - 10 minutes, or until tops and edges of cookies are browning.
Let cookies cool on the baking sheets for 5 to 10 minutes, then transfer them to a wire rack to cool completely.