PREHEAT oven to 350 degrees F; prepare 9-inch springform or round cake pan with non-stick cooking spray and set aside.
SIFT flour, baking soda, salt, cinnamon, ginger and allspice together in a medium bowl and set aside.
IN a large bowl with an electric mixer, or in a stand mixer fitted with the whisk attachment, blend butter and brown sugar until well combined; add eggs, mixing well after each addition; blend in molasses and mix well.
ADD buttermilk and dry ingredients alternately until all ingredients are combined, and mix for 2 minutes.
POUR into prepared pan and bake for 40-45 minutes or until a tester inserted in the middle comes out clean.
COOL completely before serving.