Preheat the oven to 375°F. Get out two cookie sheets; they don't need to be greased. If you're making shaped cookies using a cookie press, (e.g., spritz cookies), chill the cookie sheets as you make the dough., Cream together the butter, sugar, cream cheese, salt, vanilla, and spices., Beat in the egg yolk, then stir in the flour., If you're using a cookie press, follow the directions that come with the press to pipe cookies onto the baking sheets., Or drop the dough by the teaspoonful onto the baking sheets; a teaspoon cookie scoop works well here., Top with colored sugar, if desired., Bake the cookies for 10 to 16 minutes, until they're brown around the edges., Remove the cookies from the oven, and let them rest on the baking sheet for 5 minutes before transferring to racks to cool. Be sure to move the cookies to a rack before they're totally cool, as otherwise they may stick to the pan.