In a medium bowl, whisk together flour, baking soda, spices and salt; set aside.

In the bowl of an electric stand mixer fitted with the flat beater/paddle attachment, cream together butter and brown sugar on medium speed until somewhat light and fluffy but still grainy, 1½ to 2 minutes.

Beat in molasses until well incorporated, about 10 seconds. Add egg and beat until smooth and mixture no longer looks curdled, about 25 seconds. Beat in milk until well combined. Scrape down the sides of the bowl with a rubber spatula several times during mixing.

Add half of the flour mixture and beat on low speed until mostly combined, about 15 seconds. Add remaining dry ingredients and beat just until evenly blended. Do not over mix. The dough will be rather stiff but still soft and smooth. Place a piece of plastic wrap directly over the surface of the dough to cover it and refrigerate for about 2 hours.

Preheat your oven to 350°F. Line two large baking sheets with parchment paper and set aside.

Place granulated sugar in a small bowl. Roll heaped tablespoons of dough into balls and then roll them around in sugar to coat. Transfer dough balls to baking sheets, spacing them 2-3 inches apart, and flatten slightly. Bake until cracked on the surface and lightly browned around the edges, 10-12 minutes. Let cool for 30 seconds on baking sheet before transferring individually to a wire rack to cool completely.