Preheat oven to 350F
In a large bowl, add melted butter, granulated sugar, and brown sugar and combine
Add egg, vanilla, and molasses to the wet ingredients
Add dry ingredients (flour, baking soda, cinnamon, ginger, salt) and fold until smooth
Transfer batter to a lined 8x8 baking dish
Bake at 350F for 23-25 minutes
Allow gingerbread cookie bars to cool completely
For icing: Add cream cheese and butter to a stand mixer and mix on high speed for 2 minutes
Add confectioners sugar and milk to the mixer and mix on high for 5 minutes
Top cooled cookie bars with icing and enjoy
