Sweet potatoes are commonly used in the Southern US to make pies and puddings, they're also used in the Carribean particularly Jamaica. If you do an on-line search or look at any american cookery web site you'll find loads of recipes. This is one of my favourite pudding recipes. A similar mix is also used as the filling for a sweet potatoe pie, using a sweet shortcrust pie case.
Sweet potatoes....2 large,cooked then mashed
Eggs...2..seperated
Butter ....2oz
Light brown sugar...3oz
Milk ....4oz...approx
Salt....1/2 tspn
Cinnamon....1/2 tspn
Nutmeg....1/4 tspn
Ginger....large pinch
Cream the butter and sugar then add the beaten egg yolks and spices, then add the mashed potatoes and enough milk to give a soft, but not wet, mix.
Beat the egg whites till stiff and fold into the mix.
Pour into a buttered casserole dish and bake at 180C for about 35-40mins. Serve hot with cream or ice-cream.