Measure the first 6 ingredients into a bowl and combine well. Add milk and mashed banana. Mix and scrape into an 8 inch (20cm.) casserole or pan that has been sprayed with Pam. In the same bowl mix sugar and cocoa together. Add hot water and rum extract (if using). Stir to dissolve sugar. Pour over batter. Do not stir. Bake, uncovered, in 350 degree oven for about 40 minutes unitl batter has risen above sauce and is firm to touch. Sprinkle grapenuts over top, once you have taken pudding out of oven.

original recipe was way too sweet. Recipe taken from: Desserts cookbook from Company's Coming by Jean Pare.