Preheat your oven to 350°F (175°C). Line 2 baking sheets with parchment paper or silicone baking mats to help the cookies bake evenly and prevent sticking.

In a medium bowl, whisk together the gluten free flour blend, baking soda, baking powder, and fine sea salt until well combined. Set aside.

In a large bowl, using a hand mixer, stand mixer, or a sturdy spoon, beat the softened butter, granulated sugar, and light brown sugar together on medium speed for 2–3 minutes, until light, fluffy, and slightly pale.

Add the eggs one at a time, mixing on low just until each is incorporated. Scrape down the sides of the bowl as needed. Mix in the vanilla extract just until combined; do not overbeat.

Add the dry ingredient mixture to the wet ingredients in two additions, mixing on low or folding with a spatula just until no streaks of flour remain. The dough will be thick but not dry. If it seems very sticky and loose, let it rest for 5–10 minutes to allow the gluten free flour to absorb moisture.

Using a spatula or wooden spoon, fold in the chocolate chips and, if using, chopped nuts until evenly distributed throughout the dough.

Use a medium cookie scoop or tablespoon to portion the dough into balls, about 1 1/2 tablespoons each. Place them on the prepared baking sheets at least 2 inches apart. For slightly thicker cookies, you can chill the dough balls for 20–30 minutes, though this is optional.

Bake one sheet at a time on the middle rack for 10–12 minutes, or until the edges are lightly golden and the centers look set but still soft. The cookies will firm up as they cool, so avoid overbaking.

If desired, sprinkle a small pinch of flaky sea salt on each cookie immediately after removing from the oven. Let the cookies cool on the baking sheet for 5 minutes, then transfer them to a wire rack to cool completely.

Repeat scooping and baking with the remaining dough. If your kitchen is warm, keep the dough in the refrigerator between batches for slightly thicker cookies. Serve slightly warm or at room temperature.