In a medium mixing bowl, combine the gluten-free flour, almond flour, baking soda, and salt. Whisk together until the mixture is well blended. Set aside for later use.

In a skillet over medium-low heat, melt the butter, stirring every so often. As the butter melts, it will start to foam. Keep stirring to ensure the milk solids do not stick to the bottom of the pan. Watch closely as the butter transitions from yellow to a deep golden brown, releasing a rich, nutty aroma. Once this transformation occurs, remove it from the heat and pour it into a mixing bowl right away.

Add the milk, brown sugar, and granulated sugar to the browned butter. Whisk until everything is fully incorporated and the mixture is smooth.

Beat in the egg and vanilla extract, mixing until the texture becomes creamy and uniform.

Using a rubber spatula, fold in the dry ingredients gradually until the dough is smooth and everything is evenly combined. Gently stir in the chocolate chips until they are well distributed throughout the dough.

Cover the bowl with plastic wrap and let the dough rest at room temperature for 30 minutes. Alternatively, you can refrigerate the dough for up to 5 days if you prefer to bake later.

When you’re ready to bake, preheat your oven to 350°F (180°C). Prepare baking sheets by lining them with parchment paper or silicone baking mats.

Scoop the dough into balls, roughly 2 tablespoons each, and place them on the prepared baking sheets, ensuring they are spaced about 2 inches apart to allow room for spreading.

Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden and the centers appear just set. Avoid over-baking to keep the cookies soft.

Remove the cookies from the oven and allow them to cool on the baking sheet for 5 minutes. If desired, sprinkle with a pinch of flaky sea salt while still warm. Transfer the cookies to a wire rack to cool completely before serving.