Gluten-Free Chocolate Chip Oat Cookies
Step 1
Place racks in upper and lower thirds of oven; preheat to 350°. Toast 1 cup (100 g) coarsely chopped pecans or walnuts on a rimmed baking sheet, tossing halfway through, until slightly darkened in color and fragrant, 6–8 minutes. Transfer to a plate and let cool.
Step 2
Meanwhile, finely grind ¾ cup (75 g) old-fashioned oats in a blender, then sift through a fine-mesh sieve into a small bowl; discard pieces left in sieve. You should have ½ cup (63 g) oat flour. Mix 1 cup (packed; 200 g) dark brown sugar, ½ cup (1 stick) unsalted butter, melted, slightly cooled, 2 tsp. vanilla bean paste or vanilla extract, 1½ tsp. Diamond Crystal or 1 tsp. Morton kosher salt, and 1 tsp. ground cinnamon in a large bowl until combined. Whisk in 1 large egg, then add ¾ tsp. baking soda, ½ tsp. xanthan gum, and oat flour and whisk vigorously 1 minute.
Step 3
Add pecans, 3½ oz. (100 g) semisweet chocolate, coarsely chopped (about ½ cup), 1 cup (160 g) dried tart cherries, and remaining 1½ cups (150 g) old-fashioned oats and fold into batter with a large rubber spatula until evenly distributed. Cover bowl with a plate or plastic wrap and let dough sit at room temperature 1 hour to hydrate oat flour.
Step 4
Using a #16 cookie scoop or ¼-cup measuring cup, portion out dough and divide between 2 parchment-lined baking sheets, spacing about 2″ apart (cookies will spread as they bake; you should have about 7 cookies per sheet). Press down on cookies gently to flatten slightly, then lightly sprinkle with flaky sea salt if desired.
Step 5
Bake cookies, rotating baking sheets top to bottom and front to back halfway through, until edges are golden brown (centers will still look underbaked), 10–13 minutes. Remove baking sheets from oven. For more perfectly shaped cookies (no obligation!), working one at a time, place a glass or round cutter with a diameter larger than the cookies over or around them and scoot back and forth and in a circular motion to push edges smooth, making a neat circle. Let cookies cool on baking sheets 10 minutes, then transfer to wire racks and let cool completely (warm cookies will be fragile but will firm as they cool).
Do Ahead: Cookies can be baked 1 day ahead. Store airtight at room temperature.