The best chocolate cake

For the cake:
Preheat to 350 degrees. Line a 9×13 inch cake pan with parchment paper.
Sift together the flour, sugar, salt, baking soda, baking powder and cocoa powder into a large bowl and whisk to combine.
Add the sour cream, buttermilk, eggs, vanilla and vegetable oil to a medium bowl and whisk together, then pour in the coffee and mix once more.
Add the wet ingredients to the bowl of dry ingredients.
Whisk to combine then mix on low for about a minute.
Pour the batter into the lined tin. Bake for about 50 minutes or until a toothpick inserted in the center comes out clean.
Leave to cool for a few minutes then invert onto a rack. Peel off the parchment paper and let cool completely.

For the Frosting:
If you are using a good liquid fudge, make it. If you don’t have this on hand, melt about 1/4 cup milk or cream with 1/4 cup dark chocolate, stir to combine then let cool. Cream the butter in a stand mixer fitted with a paddle attachment. Stir in cocoa powder and salt and mix until combined.
Add the icing sugar in a few batches, mixing over low heat. Scrape the bowl and mix once more.
Add the fudge or ganache and mix until well combined. You can add milk or cream in a tablespoon at a time to thin the consistency if necessary.