In a large bowl, cream together the butter and brown sugar until smooth. Stir in molasses and egg yolk. Combine the flour, salt, baking powder, baking soda, cinnamon, cloves, ginger, and nutmeg; blend into the molasses mixture until smooth. Cover, and chill for at least one hour.
Preheat the oven to 350 degrees F (175 degrees C). On a lightly floured surface, roll the dough out to 1/4 inch thickness. Cut into desired shapes with cookie cutters. Place cookies 2 inches apart on ungreased cookie sheets.
Bake for 8 to 10 minutes in the preheated oven, until firm. Remove from cookie sheets to cool on wire racks. Frost or decorate when cool.