Place oil in your cast iron pan (or just your regular cornbread baking dish) and put it in the oven while the oven preheats to 425 degrees.Mix cornmeal, flour, sugar, baking powder and salt in a medium bowl.Add water and vinegar to the mixture and blend well.When the oven has preheated fully, carefully remove the oil from the oven and pour it into the cornbread mixture.GENTLY mix until all ingredients are combined.Pour mixture into the baking dish and place in the oven for 20-25 minutes or until knife comes out clean.Remove from oven and allow to cool for 5-10 minutes before devouring like the crazed cornbread-zombie you are...LOL!