Beat butter using a mixer at medium speed; gradually add sugars and beat until creamy. Add eggs, one at a time, beating well after each addition and scraping down the sides of the bowl.
Combine flour, baking powder, salt, cinnamon, and baking soda. Add to egg mixture alternately with milk, beginning and ending with dry ingredients. Stop mixer and add molasses. Restart mixer and slowly add whiskey. Mix until smooth, about 30 seconds. Batter will be thin.
Pour into greased 9-inch springform pan. Bake 35-40 minutes, until wooden pick inserted in the center comes out clean. Serve warm. Serves 8.