In a large bowl, stir together the flour, cocoa, sugar, baking soda, baking powder and salt. Add in the eggs, buttermilk, oil and vanilla and stir. On medium speed mix the ingredients for about 3 or 4 minutes. Mix the instant coffee in with the boiling water. Pour the coffee into the batter and stir. Batter will be thin. Pour half of batter into one 9" round cake pan and the other half into the second 9" round cake pan.
Bake in a preheated 350 degree oven for about 30 to 35 minutes, until a toothpick inserted in the middle of the cake comes out clean. Cool for 10 minutes before removing from pans. Let them cool completely on baking racks before frosting.