Preheat oven to 350°. In a large bowl, cream butter and sugar until light and fluffy. Add 1 egg at a time, beating well after each addition. Beat in pumpkin. In another bowl, whisk flour, baking powder, salt and baking soda; add to creamed mixture alternately with buttermilk, beating well after each addition. Batter will be thick.
Remove 1/2 cup batter to a small bowl; stir in cinnamon and molasses until blended. Pour half of the remaining plain batter into a greased 8×4-in. loaf pan; dot with half of the cinnamon batter. Repeat layers. Cut through batter with a knife to swirl.
Bake until a toothpick inserted in center comes out clean, 45-50 minutes. Cool in pan 20 minutes before removing to a wire rack.For coating, in a small bowl combine melted butter and maple syrup. In another shallow bowl, combine sugar, brown sugar and cinnamon. Brush loaf with butter mixture, allowing butter to soak into bread; gently roll loaf in sugar mixture, pressing lightly to coat.