Preheat oven to 350°F.
In a bowl, whisk together melted butter and both sugars.
Whisk in molasses, egg, and vanilla.
Once well combined, fold in flour, baking soda, cinnamon, ginger, cloves, and nutmeg. This will form a thick batter. Do not over-mix.
Pour into a prepared (lined and greased) 8x8 square pan. Spread out evenly.
Bake for 15-18 minutes, or until a toothpick comes out clean.
While it cools, prep the frosting. In a stand mixer cream together cream cheese and butter on medium speed for 3-5 minutes.
Add in powdered sugar and vanilla and continue mixing until a smooth and thick frosting has formed.
For thicker frosting, add more sugar until desired preference has been reached.
Once the bars have completely cooled, frost and decorate with sprinkles and gingerbread men (optional).
Enjoy!