Preheat oven to 325 and line 3 8 inch cake pans with parchment circles and spray with baker's joy or grease and flour them. In a bowl, whisk the flour, baking soda, baking powder and salt together.
Whisk the hot coffee or water with cocoa powder until smooth. In a mixing bowl, whisk the sugar, oil, vanilla and melted butter. Then whisk in the eggs and yolk. Finally whisk in the buttermilk and coloring, then the coffee and vinegar.
Sprinkle the flour mix over the wet mix and fold together until well combined. Measure the batter equally between 3 pans (I used a scale for this) and bake them for 25-30 minutes, rotating their positions half way through. The cake is done when springy in the center and a toothpick comes out clean. Don't overbake so check them after 20 minutes.
After they cool slightly, run a sharp knife around the inside of the pan, then let them cool completely then turn out from the pans.
To make the frosting: Whip the butter, cream cheese and vanilla on medium high until fully mixed and light and fluffy. Add in the powdered sugar and whip again. Leaving the mixer running, add a stream of cream until the frosting is a nice fluid, fluffy consistency and then whip another few minutes.
Place the first cake layer on a stand and add enough frosting to make a thin layer. Add the second cake and repeat. Add the top layer and use the rest of the icing to frost the top and outside of the cake. Chill in the fridge until ready to serve, then allow to stand 30 min to 1 hour at room temp before serving.