Steamed chocolate pudding with caramel sauce

Butter two 1 litre pudding bowls. In preparation for steaming, bring water to boil in two large saucepans (1/3 full). Cream butter, sugar and golden syrup together until light and fluffy. Add egg yolks one at a time and beat thoroughly. Sift flour, baking powder and salt together twice and add to creamed mixture, alternating with milk. Whisk egg white to a soft peak, gently fold into mixture. Pour half the mixture into pudding bowl, crumble flake over, add remaining mixture and smooth the top. Repeat with the second pudding bowl. Cover with a round of pleated greaseproof paper, tie securely with a string (make a handle on top for easy lifting). Lower puddings into gently boiling water, cover with a well-fitting lid and steam slowly for 2 hours (do not open or the pudding will deflate). Drizzle caramel sauce over pudding before serving. TO MAKE CARAMEL SAUCE: Put sugar into a heavy-based pan with 85 ml cold water. Heat gently until sugar has dissolved. Simmer until syrup is a rich golden colour. Remove from heat, and very carefully add 170 ml cold water. (A word of caution: caramel will splutter.) Leave to stand for 10 minutes, then pour over the pudding.