In a large mixing bowl, cream the butter and brown sugar.
Beat in eggs, molasses, and vanilla. Combine the flour, ginger, cloves, cinnamon, baking soda, and salt in a bowl. Add the flour mixture to the creamed mixture alternately with the buttermilk.
Refrigerate dough for 1-2 hours. When you are ready to bake cookies, roll in small balls (I use small ice cream scoop). Put on cookie sheets about 3" apart. Bake at 350° for 8-10 minutes. The cookies will crack in the middle.
For the frosting beat the butter until smooth using a stand or hand mixer. Add in the vanilla and ginger. Slowly add the powdered sugar along with a teaspoon of milk at a time until you have smooth consistency.