In a food processor fitted with a steel blade, combine flour, brown sugar, cinnamon, ginger, cloves, salt, and baking soda. Pulse for about 10 seconds until mixed.
Scatter butter pieces over the mixture. Process for around 15 seconds until the mixture resembles very fine meal.
With the machine running, gradually add molasses and milk. Process until the dough is moist and forms a soft mass, about 10 seconds.
For a stand mixer, combine dry ingredients and mix on low for 30 seconds. Add butter, mix for 1.5 minutes until sandy, then add molasses and milk in a similar manner.
Scrape dough onto a work surface and divide in half. Roll one portion out to ¼ inch thick between parchment paper.
Freeze the rolled dough on a cookie sheet for 15 to 20 minutes, or refrigerate for 2 hours.
Preheat oven to 350 degrees F. Line cookie sheets with parchment paper.
Remove one sheet of dough and cut out shapes with cookie cutters. Place on prepared sheets, ¾ inch apart.
Bake for 8 to 11 minutes until set in the center, rotating sheets halfway through for even baking.
Cool cookies on sheets for 2 minutes, then transfer to a wire rack to cool completely.
Gather scraps and repeat the rolling and cutting process until all the dough is used. Decorate cookies with royal icing if desired.
