This gluten-free double chocolate cookie recipe uses buckwheat flour for a nutty flavour. These cookies taste like brownies. This recipe requires a stand or electric hand mixer!
– 6 tablespoons unsalted butter – 12 ounces bittersweet chocolate (60–70% cacao mass)*, chopped (about 2 ¼ cups), plus several chunks for the tops of the cookie – ½ cup buckwheat flour – 2 tablespoons tapioca flour** – ¾ teaspoon baking powder – 2 large eggs, at room temperature*** – ½ cup plus 2 tablespoons cane sugar – ½ teaspoon fine sea salt – 1 teaspoon vanilla extract – Flaky salt such as Maldon, for the top
Set racks in the upper and lower thirds of the oven and preheat to 350°F. Wrap two rimless cookie sheets in parchment. Put butter in a small, heavy-bottomed saucepan over low heat.
Place 8 ounces of chocolate (not all!) Stir often to avoid scorching the chocolate. Continue cooking until the mixture feels warm but not hot. Stay warm after removing heat.
Put buckwheat, tapioca, and baking powder in a small bowl. Beat eggs, sugar, and salt in a stand mixer bowl with the paddle attachment on medium-high speed for 5 minutes until fluffy.
After whipping vanilla on low, add warm chocolate butter. Add flour and mix slowly. After removing the mixer bowl, fold the remaining 4 ounces chopped chocolate with a flexible silicone spatula.
Cool the batter for a few minutes to thicken like brownie batter. Drop heaping tablespoons of batter onto prepared baking sheets 2 inches apart with a #40 spring-loaded ice cream scoop or two spoons.
Add chocolate chunks and flaky salt to cookies. Puff and crack cookies and set edges in 8–12 minutes by rotating pans front to back and top to bottom halfway through baking.
Allow pans to cool. Enjoy warm or room temperature. The cookies taste best the day they're baked but can be kept airtight at room temperature for 3 days.