From 6 Bittersweets
Adapted from Bojon Gourmet and Alice Medrich
Makes sixteen 3-inch cookies
XIAOLU'S NOTES: This dough needs to rest for at least 3 hours before baking, so please plan accordingly! It also scales up very well (I made a double batch). Sweet/glutinous rice flour, such as Mochiko brand, is stickier and more finely ground than other rice flours. These qualities are important to the texture of these cookies, so do NOT substitute sweet rice flour with regular rice flour. You'll find it in any Asian grocery as well as in the Asian or gluten-free sections of many supermarkets. If all else fails, you can also order it in bulk online. I wasn't actually baking these cookies for anyone with a severe gluten allergy, but if you are, you'll want to purchase oats/oat flour that's specifically labeled gluten-free. While the current consensus seems to be that oats themselves don't contain gluten, regular supermarket oats are usually processed on the same machinery as gluten-containing foods and thus are NOT truly gluten-free. I ground my own oat "flour" using my coffee/spice grinder. It took about 15 seconds and couldn't have been simpler. Don't give in to the urge to use chocolate chips for these -- chocolate chips have ingredients added to help them keep their shape at warmer temperatures. Chopped chocolate gets wonderfully melty and is more likely to stay that way as the cookies cool. Chopping your own chocolate will also create large chunks, thinner flakes, and even some chocolate dust that will mix into your dough wonderfully to enhance the flavor and texture even more.
1/2 cup (1 stick; 4 oz.) unsalted butter
1/2 cup (3.5 oz.) packed dark brown sugar
6 Tbsp (2.7 oz.) granulated sugar
1 large egg, room temperature
3/4 tsp vanilla bean paste OR pure vanilla extract
2 3/4 oz. (about 6 Tbsp) sweet white rice flour
2 oz. (about scant 1/2 cup) gluten-free oat flour
1/2 oz. (about scant 2 Tbsp) tapioca flour
1/4 tsp baking soda
1/4 tsp salt
1/4 tsp xanthan gum
4.5 to 6 oz. semisweet OR bittersweet chocolate, coarsely chopped
1/2 cup (2 oz.) toasted pecans, cooled and coarsely chopped (optional)
Flaky sea salt, to garnish
To prepare the cookie dough, melt 6 tablespoons of the butter in a small saucepan (preferably with a light-colored bottom) over medium heat. Continue to cook, swirling occasionally, until the butter turns golden and smells incredibly fragrant, about 5 to 10 minutes. When the butter starts to foam up, watch it very closely. There should be brown bits (NOT black) on the bottom of the pan when its ready. Brown butter turns to burnt in what feels like a millisecond, so remove the pan from heat as soon as it looks ready. Immediately put the remaining 2 tablespoons of butter into the pan and swirl gently until it's completely melted.
Place the sugars in a large heat-safe mixing bowl, then pour the browned butter mixture in while it’s still hot and stir thoroughly. Let cool, stirring occasionally, for 10 minutes. Meanwhile, sift together the flours, baking soda, salt, and xanthan gum (oat flour tends to be clumpy). Set aside.
Whisk the egg and vanilla into the sugar mixture until well-combined and emulsified. Use a sturdy wooden spoon to stir the flour mixture into the sugar mixture until well combined. Next, continue to stir vigorously for 45 seconds. (The dough should firm up during this time, and the additional mixing activates the sticky power of the xanthan gum to produce chewier cookies.) Stir in the nuts and chocolate until evenly distributed.
Cover the dough, and chill in the fridge for at least 3 hours and up to 2 days until ready to bake (dough can be safely frozen for even longer).
To bake the cookies, preheat the oven to 375 degrees F and take the prepared dough out of the fridge/freezer. Line 2 large cookie sheets with parchment paper or non-stick silicone mats.
As soon as the dough has warmed enough to scoop (it should still be quite firm), scoop it into 1 1/2-inch wide balls (just under 3 tablespoons; this scoop in size large works well for me). Place the balls onto the prepared cookie sheets, spaced 2 inches apart. Crumble a little bit of flaky salt over the top of each cookie.
Bake the cookies about 9 to 12 minutes, rotating the pans halfway through. When the cookies are ready, the edges should be just starting to brown, and the tops should be puffed all over with soft centers that collapse when gently touched with a fingertip. The centers will look wet under a thin surface of dry, cracked-looking dough. They will still look underbaked at this point, but they're not. This IS how they should look -- the cookies will firm up after leaving the oven from being cooked by residual heat and then from cooling down.
Remove the cookies from the oven. If they look too puffy, slam the pan straight down on the counter 2 to 3 times to deflate them a bit. Let cookies cool on the pans for 15 minutes, then transfer them to cooling racks. Enjoy right away OR cool completely and store in an airtight container at room temperature for later. The cookies are best within 2 days of being baked.