In a bowl, combine water and baking soda. Immediately add remaining pudding ingredients; mix well. Pour batter into a well-greased 1-qt. pudding mold. (If you don't have a pudding mold, use an ovenproof bowl and cover tightly with foil.) Put a rack in the bottom of a large kettle. Place pudding mold or bowl on rack. Add boiling water to 1-in. depth. Cover kettle and boil gently, replacing water as needed. Steam 1 hour or until cake tests done. Cool for 10 minutes; unmold.
For sauce, heat all ingredients in a saucepan until butter is melted and sugar is dissolved. Serve pudding and sauce warm. Yield: 8-10 servings.