Take a ladle and take off the butter and put it in another bowl. Keep stirring until the butter comes out.
Put the milk in another kettle and start to boil, bring to boil. Sift 1/2 cup flour into the milk while beating. Continue beating until mixture is thick like pudding. Remove it from the heat, add it to the cream mixture, and beat with a wire whisk until smooth and well blended.
Pour into a 2 quart baking dish. Smooth out the top and sprinkle the cinnamon and sugar on top. Pour the butter you saved over the top. Serve warm.