In the bowl of a stand mixer fitted with the paddle attachment, beat the softened butter and packed brown sugar together on medium speed for 3 full minutes until pale, fluffy, and noticeably increased in volume.

Add the egg and beat on medium for 45 seconds until fully incorporated. Scrape down the bowl, then add the unsulfured molasses and beat on low for 20–30 seconds until the mixture is deep brown and glossy with no pale streaks remaining.

Add the dry ingredients to the wet ingredients and mix on the lowest speed for 20–30 seconds, just until no flour streaks remain. Do not overmix. The dough will be thick, dark, and slightly tacky.

Cover the bowl tightly with plastic wrap and refrigerate for 30 minutes minimum.

Preheat the oven to 350°F (175°C). Line a light-colored half-sheet baking sheet with parchment paper and allow the oven to fully preheat for at least 20 minutes.

Using a 1.5-tablespoon cookie scoop, portion the chilled dough into 30g balls, roll each between your palms until smooth, then roll fully in granulated sugar until every surface is coated. Place on the parchment-lined baking sheet at least 2 inches apart. Do not flatten.

Bake on the center rack for 10–11 minutes, until the edges are set and show dramatic crinkle lines across the tops, but the centers still look slightly soft. Do not overbake.

Let the cookies rest on the hot baking sheet for 5 minutes, then transfer to a wire cooling rack and cool for at least 10 minutes before eating.