1. In a bowl, with an electric mixer on medium speed, beat butter and sugar until very smooth. Beat in egg yolk until well blended, scraping down sides of bowl as needed.
2. In another bowl, mix flour, cardamom, and baking soda. Stir or beat into butter mixture until well blended.
3. Shape dough into 1-inch balls. Place 1 inch apart on buttered or cooking parchment-lined 12- by 15-inch baking sheets.
4. Bake cookies in a 325° oven until golden brown on the bottom, 16 to 18 minutes; if baking more than one pan at a time, switch pan positions halfway through baking. Using a wide spatula, transfer the cookies to racks to cool completely.
Note: Nutritional analysis is per cookie.