The lovechild of a brownie and a cookie - enough said. Surprisingly, these decadent cookies are flourless and butter-free, making them a slightly less guilty treat. Recipe only very slightly adapted from Bon Appetit.
Place oven racks on upper and lower thirds of the oven. You will be making two cookie sheets at the same time. Preheat oven to 350 degrees F.
Mix the dry ingredients together (powdered sugar, cocoa powder, salt). Add the eggs. Then fold in the chocolates. The batter will be very thick.
Line two baking sheets with parchment paper. Grease a tbsp-sized cookie scoop or measuring spoon and place batter onto the sheets, placing at least 2" apart.
Bake for 14 minutes, rotating the sheets from bottom to top at the 7 minute mark. Cookies will be puffed and cracked, and just set. Allow to cool on a wire rack on the baking sheet to firm up. Sprinkle with flaky sea salt while the cookies cool.
Cookies are best served warm and gooey out of the oven, but will be good for approx. 3 days. Store at room temperature in an air-tight container.