Preheat the oven to 325 degrees F. Grease three 8-inch round cake pans and line the bottoms with parchment.
Combine the chocolate, cocoa and instant coffee. Pour the hot water over to melt; let sit 2 to 3 minutes and then whisk until smooth.
Add the sugar, flour, baking soda, baking powder and salt into mixer bowl and mix on low with the paddle attachment to combine.
Add the buttermilk to the chocolate mixture to cool it slightly more.
Whisk together the oil, eggs and vanilla.
Add the chocolate and wet ingredients to the dry. Turn the mixer on low and combine until the dry is moistened. Raise the mixer speed to medium and beat for 2 minutes, scraping halfway through.
Scrape into pans and bake until a toothpick comes out with a few moist crumbs, 25 to 30 minutes. Allow the cakes to cool in the pans for 15 minutes, and then turn onto a rack to cool. Wrap tightly in plastic wrap.