You can use Murphy's or Guinness.
Espresso, though optional, boosts chocolate cake flavor.
Instead of buttermilk, use ordinary milk with 1 tablespoon of white vinegar per cup.
Oil. I prefer oil over butter for cakes since it's moister. Use avocado, vegetable, or neutral-flavored oil.
Pre-heat the oven to 350f and place the rack in the middle.
Cover a 9x13 inch cake pan with parchment paper and set aside.
Mix 3 cups (390g) of all-purpose sifted flour, 2/3 cup (83g) of cocoa powder,