Heat oven to 350 degrees F.
Spray an 8-inch square pan with baking spray. Set aside.
Whisk together flour, baking soda, baking powder, and gingerbread spice. Set aside.
With an electric mixer, beat butter and sugar until light and fluffy, about 2-3 minutes.
Add eggs, one at a time, beating well after each addition.
Stir in molasses.
Add flour mixture alternately with buttermilk, beginning and ending with flour mixture.
Pour into prepared pan.
Bake for 35-40 minutes, or until cake tests done.