Pick over and wash prunes, then soak one hour in cold water, and boil until soft in same water. Obtain meat from stones and add to prunes and water; then add sugar, cinnamon, boiling water, and simmer ten minutes. Dilute corn-starch with enough cold water to pour easily, add to prune mixture, and cook five minutes. Remove cinnamon, add lemon juice, mould, then chill, and serve with cream.