• Preheat your oven to 350 degrees Fahrenheit. Grease an 11x9 inch baking dish with butter then sprinkle some cocoa powder over the top. Shake the baking sheet so the cocoa powder covers the butter.
• Pour half the can of Guinness into a small pot and bring it to a boil over high heat. Set the pot aside.
  440 ml can of Guinness
• While the Guinness is heating, make the rest of the cake. Whisk the flour, sugar, cocoa powder, baking soda, baking powder, and salt together in a large bowl. Add the oil, vinegar, and the remaining Guinness in the can and whisk. Pour the hot Guinness into the bowl and carefully whisk it into the batter. Stir in the chocolate chips.
  2 cups flour, 2 cups sugar, ¾ cup cocoa powder, 2 teaspoons baking soda, 2 teaspoons baking powder, 1 teaspoon salt, ½ cup neutral-flavored oil, 2 teaspoons vinegar, ½ cup chocolate chips
• Pour the batter into the prepared baking dish and bake in the oven for 25-30 minutes, or until a toothpick inserted into the middle of the cake comes out clean. After 10 minutes, remove the cake from the baking dish and let it cool completely on a cooling rack. Once it is completely cool, cover it with the frosting.

Irish Whiskey Buttercream

• Place the butter, powdered sugar, and Irish whiskey in a large bowl. Cream together using electric beaters. For a thinner frosting, use more whiskey.
  ½ cup softened butter, 1 ½ cups powdered sugar, 1 ½ tablespoons Irish whiskey