Preheat oven to 350°F.
Grease two 8" (or three 6") round cake pans. Line the bottom with parchment paper.
Add flour, sugar, cocoa powder, salt, baking powder and baking soda to your mixing bowl (I use a stand mixer with the whisk attachment). Stir until combined.
In a medium bowl, whisk together the oil, buttermilk, eggs and vanilla. Once combined, add in the coffee slowly so you don't cook the eggs.
Pour the wet ingredients into the dry ingredients and stir slowly until combined. Then mix on high for two minutes, scraping the sides halfway through.
Distribute the batter between the two prepared pans.
Bake for 35-45 minutes, or until a toothpick comes out clean. (A few moist crumbs sticking to the toothpick is fine, but you don't want it gooey).
Cool for a few minutes. Run a butter knife around the outside of each pan, and turn the cakes out onto a cooling rack.
Wrap in plastic wrap and then put in a freezer bag and freeze, if desired.