In a large bowl, stir together flour, sugar, cocoa, baking soda, baking powder, and salt. If you have a flour sifter, sift all dry ingredients.
In mixing bowl, beat oil, eggs, buttermilk, and vanilla for 1 minute. Add dry ingredients to wet ingredients and stir until combined. Pour in hot water and mix together.
Spray two 8 or 9-inch cake pans with non-stick cooking spray. You can also use three 8 inch cake pans for this recipe. Pour batter evenly into each pan. Bake at 22-27 minutes. Place toothpick or cake tester in the center of the cake to check if it comes out clean.
Let cool before frosting.
To make Chocolate Buttercream Frosting:
In mixing bowl, cream together Butter, Cocoa, Powdered Sugar, and Cream until light and fluffy. You may want to add more cream or milk depending on consistency. Once the cake has cooled and has been removed from pans, frost each layer with frosting.
Top with your favorite chocolate candy bars -- Kit Kat, Crunch Bar, Snickers, Reeses Peanut Butter Cups, Twix, Milky Way, Butterfinger, and M & M's.
This is one baked good that gets even better the next day if covered.
*If you would like to make a triple layer cake, 1 ½ times the recipe and use three 8 or 9-inch cake pans.