In a medium bowl, whisk together the buckwheat flour, baking soda, and salt. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, or using a hand mixer, cream together the butter, brown sugar, and granulated sugar on medium-high speed until smooth and creamy, about 2–3 minutes.

Add the egg and vanilla and mix until well combined. Scrape down the sides and bottom of the bowl.

With the mixer running on low speed, gradually add the dry ingredients. Mix until fully incorporated, scraping down the bowl as needed. Stir in the chocolate chips.

Cover and refrigerate the dough for at least 1 hour, or overnight.

Preheat the oven to 350°F. Line large baking sheets with parchment paper or silicone baking mats.

Scoop the chilled dough into balls, about 2 tablespoons each, and place them on the prepared baking sheets about 2 inches apart.

Bake for 12–13 minutes, until the edges are set and the centers look slightly soft.

Remove from the oven and let cool on the baking sheets for 2–3 minutes. Transfer to a wire rack to cool completely.