Cookies: Preheat the oven to 350°. Line 2 cookie sheets with parchment.
Cream the butter and sugar in the bowl of a stand mixer until light and fluffy. Add the egg and beat until combined, scraping down the sides of the bowl as needed. Beat in the sorghum, scraping the bowl, until combined.
Sift together the flour, baking soda, spices, and salt into a small bowl. Gradually add to the butter mixture and beat until the dough comes together, scraping the bowl as needed.
Scoop the batter onto the prepared baking sheets, placing dough at least 1” apart. I use a small cookie scoop and bake the cookies for 8 to 10 minutes, until the cookies are brown around the edges and firm in the center.
Cool the cookies on the baking sheet for a few minutes, then remove to a wire rack to cool completely.
Glaze: Whisk confectioners’ sugar and buttermilk together in a shallow bowl until smooth. Dip the cookies upside down into the glaze for a thin, even coat that shows the texture of the cookies, or use the back of a spoon to spread a thicker glaze in the center of the cookies.