Brownie Cookies

Preheat oven to 350°F. Prepare baking sheet pans with silicone baking mats or parchment paper.
In a microwave-safe bowl, combine dark or semi-sweet chocolate chips and unsalted butter. Heat in the microwave in 30 second intervals, stirring in between each interval until melted and smooth. Set aside to cool while completing the next step.
In a large mixing bowl, combine brown sugar, granulated sugar, and room temperature eggs. Use an electric hand mixer on medium-high speed to whip the eggs and sugars for about 3 minutes until light and pale.
Add vanilla extract, instant espresso powder, and salt.
While mixing on low speed, slowly pour in the melted chocolate to temper the egg mixture. Mix on low until the chocolate is well combined with the eggs.
Add all-purpose flour and dark cocoa powder to the mixture. Mix on low speed until just combined. Scrape the sides and bottom of the bowl to ensure all the ingredients are well mixed. Do not over mix the brownie batter.
Immediately portion the brownie batter with a large cookie scoop (3 tablespoons) and place on the prepared baking sheet pans. Allow space in between the batter for spreading. Sprinkle the tops of the cookies with flaky sea salt if desired.
Bake the cookies for approximately 13-14 minutes until the edges are set and the centers are soft. Remove the baking pan from the oven and allow the cookies to cool on the pan for 2-3 minutes before transferring to a wire rack to cool completely.