How to make
Dissolve the starch, add the milk, which you've sweetened with the sugar and bring to a boil to make the cream.
Begin to stack the cake in a rectangular oven dish. Pour a little cream at the bottom, then place a layer of biscuits over the cream, then a banana layer, biscuit layer, etc.
At the very top, pour on the remaining cream generously and sprinkle with chopped walnuts. Allow the cake to sit for 6 hours before serving.