Mix the flour, sugar, cocoa, baking soda and salt together in a large bowl.With your mixer on low speed beat in the oil, vinegar, vanilla, and water until smooth.
Divide the mixture into the three 9″ prepared pans, coated with butter and dusted in flour or sugar. Bake until a cake skewer inserted in the center of the cake comes out clean.
Place the chocolate in a stainless steel bowl, over a pot of simmering water, stir with a rubber spatula as the chocolate melts, if the pan starts to get too hot, remove it from the heat.