I got Big to mash the bananas in a bowl (very cathartic) and into a milk pan, I put put 50g flaked rice, a bit under a pint of semi skimmed milk, about 3 tbs whole milk powder, about 50g ground whole almonds and the seeds from1 or 2 cardamom pods, ground. (I buy big bags of almonds cheap in supermarkets in the Indian aisle or in Indian supermarkets, then I just grind a few in the Bamix when I need them. They are more nutritious with the skins anyway. So I added the seeds to the almonds and blitzed both together.)
I heated this to a boil, simmered (stirring lots) until thickened and then I mixed it into the mashed bananas.
I allowed it to cool a little (while we ate supper) and then we tucked in. Unbelievably creamy, really easy, and super nutritious.
The ground nuts aren't necessary, or desiccated coconut or ground rice could be substituted.
This also works with soya milk, omitting the milk powder, but doesn't work with rice milk, it never thickens, unless you use cornflour or custard powder as well. Flaked rice makes it really quick and easy but pudding rice or risotto rice would also work but would need about 20 mins simmering and stirring.