Begin preheating the oven to 350° F (176° C) and line a cookie sheet with parchment paper or a silicone mat.
In a large bowl, combine the dry ingredients: the flour, baking powder and soda, salt, cinnamon, ginger, and cloves. Whisk with a fork to mix and lighten.
In a 2 cup measuring cup, combine the molasses and buttermilk, stirring well with a fork to thoroughly mix.
Add the butter and brown sugar to the bowl of a mixer and cream them together until fluffy, between 2-3 minutes. Add the egg and blend then scrape the bowl well.
Pour the molasses/buttermilk mixture into the mixer bowl and stir on low, scraping the bowl often to ensure all the butter is off the sides and up from the bottom. Everything will look a bit curdled.
On low speed, gradually add the dry ingredients and stir just until no streaks of flour are seen. Turn off the mixer and stir a few times by hand with a spatula, scraping the sides and bottom.
Drop tablespoon size (measuring spoon tablespoon size) balls of batter onto the cookie sheet a couple inches apart. Place the sheet in the oven and bake for about 12 minutes or until the cookies are no longer shiny and when poked with a finger, the indent bounces back.
Let the cookies cool on the sheet for about 2 minutes then transfer to a cooling rack. When the cookies have cooled, make the icing.
Icing:
In a large bowl, stir together all of the icing ingredients: the butter, powdered sugar, the cream or milk, and the vanilla until very well combined and the lumps are gone.
Either spoon the icing over the cookies or lightly dip the tops of the cookies into the icing bowl, allowing the excess icing to run off. Sprinkle with cinnamon if desired. Allow time for the icing to set up before serving.
Notes
**Edit: I made a butter error in the recipe that I have since corrected. I used a total of 3 sticks instead of the correct amount of 3/4 cup (1 1/2 sticks) -- you can use 3 sticks, FYI, and the cookies are fabulous. I have not tried the recipe with the correct amount of butter but I imagine they are still amazing! Me, I'll likely continue to use 3 sticks as heh, they were excellent that way!Adapted from Foodess.