Cook the quinoa. Rinse 1/2 cup quinoa under cold water. Combine with 1 cup water in a small pot. Bring to a simmer, cover, and cook until tender, about 15 minutes. Fluff and let cool completely. You’ll use about 1 1/2 cups cooked quinoa.

Prep your station. Line two baking sheets with parchment. Set oven to 350°F (175°C). If your kitchen is warm, plan to chill the dough later for 15–20 minutes.

Mix dry ingredients. In a large bowl, whisk flour, oats, baking soda, baking powder, salt, and cinnamon.

Combine wet ingredients. In another bowl, whisk melted butter, brown sugar, and maple syrup until smooth. Add the egg and vanilla. Whisk until glossy.

Bring it together. Stir the wet ingredients into the dry just until a few streaks of flour remain. Gently fold in the cooled cooked quinoa and your mix-ins. The dough will be thick and slightly sticky.

Chill briefly. For thicker cookies, cover and chill the dough 15–30 minutes. This helps control spread and improves texture.

Shape. Scoop heaping tablespoons (about 1 1/2 tablespoons each) onto the baking sheets, spacing about 2 inches apart. Lightly flatten the tops with your fingers or the back of a spoon.

Bake. Bake 10–12 minutes, until the edges are set and lightly golden but centers still look soft. Rotate pans halfway if your oven runs uneven.

Rest and cool. Let cookies rest on the sheet for 5 minutes to firm up, then transfer to a rack to cool fully. They’ll continue to set as they cool.

Enjoy. Serve warm or at room temperature. They’re excellent with tea, coffee, or a glass of milk.