I cannot get over how good these mini brownie crinkle cookies are! They are chewy, fudgy, and full of chocolate. Plus some flaky salt for good measure. All you need is 30 minutes, and you'll end up with 60 bite-sized, shiny-topped cookies!
Preheat the oven to 350°F (177°C). Line a full sheet pan (or two half sheet pans) with parchment paper. In a small bowl, whisk together the all purpose flour, cocoa powder, espresso powder (if using), baking powder, and Kosher salt. Set aside.
Fill a small pot with 1-2 inches of water and bring it to a gentle simmer. Add the dark chocolate and unsalted butter cubes to a heatproof mixing bowl. Set the bowl over the simmering water, making sure that the water doesn't touch the bottom of the bowl. Stir constantly, just until the chocolate mixture is smooth and completely melted. Let it cool slightly.
Meanwhile, add the dark brown sugar, granulated sugar, and egg to a large mixing bowl. Using a whisk attachment, whip the egg and sugars together for a full 6-7 minutes, until it's lighter in color, nearly doubled in volume, and looks similar to cake batter.
With the mixer running, slowly drizzle the melted chocolate into the sugar-egg mixture until smooth. Scrape down the sides of the bowl every once in a while to make sure everything is well-combined. Stir in the vanilla extract. Then, fold the dry ingredients into the batter, just until the dough is combined.
Using a #100 cookie scoop or teaspoon, quickly scoop the dough into small balls, and place them about one inch apart on the prepared sheet pan. (The temperature of the dough is important for shiny, crinkly tops, so you'll want to work as quickly as possible. See the Recipe Notes for more details.)
Bake the cookies for 5-6 minutes, flipping the pan halfway through, just until the edges are set and the centers are still a bit underdone. The tops will still be a little shiny. Let the cookies cool on the pan for about 5 minutes, and then transfer them to a wire rack to cool completely. Sprinkle the cookies with flaky salt, to taste. Enjoy!
Notes
To make sure the recipe comes out great every time, use a kitchen scale to weigh the ingredients instead of using measuring cups. If you don’t have a scale, then use the fluff-and-spoon method to measure the flour and cocoa powder. First, whisk the flour or cocoa powder until it’s nice and fluffy. Then, spoon the fluffed flour or cocoa powder into a measuring cup and level it off without packing it in.Use a good-quality dark chocolate like Ghirardelli or Guittard. You can use chocolate chips or a chopped bar.I use superfine sugar in this recipe, because it dissolves more, which makes for even shinier tops. But you can use granulated, just keep in mind that the courser the sugar, the more dull the cookies will look. However, it won't affect taste whatsoever.If you want shiny tops, you'll need to work quickly! The more the dough cools, the duller the cookies will be on top. I like to use a full sheet pan so I can bake almost all of the cookies at once. If you only have half sheet pans, it's fine, just keep in mind the second batch of cookies won't be as shiny. (But they'll taste just as delicious!)For chewy, fudgy cookies, it's important to under-bake the cookies just a bit. The cookies should be set on the edges, but still a bit shiny on top.Store leftover cookies in an airtight container for 2-3 days.