Preheat the oven to 180 C. Grease and lightly flour two 9-inch round cake pans.
In a medium bowl, mix flour, spices, baking powder and baking soda together and lightly whisk. Set aside.
In a large bowl, beat the butter until smooth, then add the sugars and beat until light and fluffy. Add the molasses, then eggs and beat well. Add in the ginger.
Alternate between adding the flour and the milk to the batter.
Evenly distribute the batter to the cake pans and bake for 35-40 minutes, or until a toothpick comes out clean.
Remove the pans and allow to cool.
Butter Cream : Beat the butter until completely smooth and creamy.
Add the powdered sugar slowly, one cup at a time. Add the ground cinnamon and extract.