1. Preheat oven to 400 degrees.

2. In a large bowl, mix together the sugar, flour, baking soda, and cinnamon and set aside.

3. In a saucepan, mix the water, butter, oil, and cocoa powder. Bring this to a boil while stirring and add it to the dry ingredients bowl and mix well.

4. Add in the milk, egg, and vanilla and mix well.

5. Pour into a 10-inch iron skillet and bake for 18-20 minutes or until baked through. Cool for about 20 minutes.

6. For the frosting, combine the butter, cocoa, and milk and bring to a boil while stirring. Remove from heat and add in the powdered sugar and half the pecans and stir well. Pour over the cake and spread it all over. Sprinkle the remaining pecans over the top. Let the frosting set and then serve.