In the bowl of an electric mixer fitted with the paddle attachment, cream together the butter and the brown sugar until light and fluffy. Mix in the molasses, then beat in the egg, scraping down the sides of the bowl as needed.
In a separate bowl, whisk together the flour, baking soda, and salt. Add half this dry mixture to the mixer bowl and stir it in on low, then mix in the rest.
The dough is soft so cover the bowl with plastic wrap and chill it in the refrigerator for at least 1 hour.
Preheat the oven to 350ºF. Line a baking sheet with parchment.
Roll 40 grams of dough into round balls, then roll them in the turbinado to coat them on all sides. Place the cookies on the prepared baking sheet, spacing them about 2 inches apart. Bake the cookies for about 11 minutes or so, the edges will be firm. Let cool 5 minutes on the pan before transferring to a cooling rack.