Whisk self-rising flour, sugar, eggs, evaporated milk, and water together in a saucepan placed over medium-high heat. Whisk constantly while bringing mixture to a boil. Reduce heat to medium-low. Whisking constantly, cook pudding at a simmer until thickened, about 15 to 20 minutes.
When pudding has thickened, stir in margarine and vanilla extract until thoroughly combined.
Remove pudding from heat and set aside for about 10 minutes to cool. Sprinkle pudding with cinnamon; serve warm.
Tips
You can substitute 3 cups regular milk for evaporated milk if you want to deviate and make regular plain pudding.
When making this dish, I reuse the empty PET Milk can to fill with water as my measuring cup. It's a little less than a cup of water.
My grandmother says to wait until it's firm and cooked well to add 1/4 to 1/2 cup butter, but I usually grow impatient. It cooks in about 15 to 20 minutes and will thicken to a texture closely resembling oatmeal.
