Heat the oven to 350 degrees. Grease three 9-inch round cake pans, and line the bottoms with parchment paper.
In a large bowl, whisk together the flour, sugar, cocoa, baking soda and salt.
In a separate bowl, whisk together the oil, milk, eggs and vanilla.
Add the wet ingredients to the dry ingredients, and whisk until combined. Gradually add the hot coffee, and whisk until smooth, scraping the bottom and sides of the bowl to make sure no dry ingredients remain. The batter will be thin.
Divide the batter evenly among the prepared pans. Bake on the center rack for 25-30 minutes, or until the centers spring back lightly when touched, and a toothpick inserted in the center comes out clean or with a few moist crumbs. Cool in the pans for 10 minutes, then turn the layers onto wire racks, and cool completely.