Melt the chocolate in a double boiler or use the microwave. Microwave in 20 second increments, stirring after each until completely melted. Set aside to slightly cool (so it doesn’t melt the butter or cook the eggs).

Whisk the flour, cocoa powder, espresso powder, baking powder, and salt together. Set aside.

In a large bowl using a handheld or stand mixer fitted with a paddle attachment, beat the butter, brown sugar, and granulated sugar together on medium-high speed until smooth and creamy, about 3 minutes. Add the eggs and vanilla extract, and beat on high speed for 2 full minutes. Scrape down the sides and up the bottom of the bowl, then beat on high for 1 more minute. Pour in the slightly cooled melted chocolate and mix on medium-high speed for 2 full minutes.

Pour in the the dry ingredients and beat on low speed until combined. Finally, beat in the chocolate chips.

Preheat oven to 350°F (177°C). Line large baking sheets with parchment paper or silicone baking mats. As the oven preheats, continue to step 6.

Cover and chill the dough in the refrigerator for just 20 minutes as the oven preheats. This quick chill time helps slightly solidify the chocolate and butter in the dough, which gives the cookies a nice spread. If chilling for longer than 20 minutes, allow the dough to sit at room temperature for 15 minutes before rolling and baking.

Roll or scoop the dough into balls, 1.5 Tablespoons of dough each. Place 3 inches apart on the baking sheets and bake for 12-13 minutes or until the edges appear set.

Remove from the oven and allow cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.

Cookies stay fresh covered at room temperature for up to 1 week.