Combine the sugar, flour, cocoa powder, baking soda, baking powder, and salt into a bowl. Stir together with a whisk until evenly combined
Add the vanilla, eggs, buttermilk, and oil and stir until combined
Once combined, add the hot coffee. Stir quickly to ensure the hot coffee is evenly distributed. The batter will be very thin
Pour the batter into 3 greased and floured 9" round cake pan and cook for ~30-40 minutes (ovens vary so test with a toothpick in the center and remove when it comes out clean) 350 F – make sure a toothpick comes out clean
Set aside to cool