Preheat the oven to 350 degrees F. Combine the flour, sugar, baking powder, baking soda, salt, and cocoa powder in a bowl. Mix well. In a mixing bowl, beat the oil, eggs, vanilla, and milk with an electric mixer on medium speed until uniform in color. With the mixer running, slowly add the flour mixture to the egg mixture. Mix well. Add the hot coffee to the mixture and beat on medium speed until incorporated. Transfer the batter to a 9x13 baking dish, or divide between 2 9-inch square pans. Place in the oven and bake at 350 degrees for 35-40 minutes or until the cake tests done when a toothpick is inserted in the middle. Remove the pan from the oven and let cool in the pan for 10 minutes then transfer the cake to a cooling rack to cool completely. Store the cake in an airtight container.