Add the butter and brown sugar to a bowl and use a mixer to beat them together until light and creamy. Add the molasses, vanilla, and egg, and beat until creamy again.
In a separate large bowl, stir together the flour, baking soda, salt, ginger, cinnamon, cloves, and nutmeg.
Add about ⅓ of the flour mixture to the butter and sugar mixture, then beat on low speed until incorporated. Repeat until all of the flour has been added to the batter. It should form a very soft cookie dough.
Transfer the cookie dough to a large piece of plastic, shape it into a ball, and wrap it tightly. Refrigerate for at least two hours, or up to one day.
When ready to make the cookies, preheat the oven to 350ºF. Divide the cookie dough in half to make it easier to work with (keep the other half in the refrigerator until ready to use). Roll the dough out on a lightly floured surface until it's about ⅛-inch thick. Cut the dough into your desired shapes and place them on a parchment-lined baking sheet, at least one inch apart.
Bake the cookies for 8 minutes, or until slightly puffed in the center and they are just beginning to brown on the outer edges. Remove the cookies from the oven and allow them to cool completely.
Icing (optional)
While the cookies are cooling, place the powdered sugar in a bowl and add 1 Tbsp water. Stir to combine, then continue to add water, a very small amount at a time, until it forms a thick icing (about 1-2 Tbsp total).
Place the icing in a plastic bag and cut a very small piece off the corner to create a piping tip. Pipe the icing onto the cooled cookies in your favorite design!