Prepare your pan, spray with pan spray and lay a sheet of parchment on it. In a small bowl combine sour cream, eggs and vanilla. In another bowl combine flour, baking soda and salt. Set aside. Pre-heat oven to 350 degrees.
in a medium pot over medium heat add butter, cocoa, sugar and coffee
Whisk until melted and it just begins to bubble then take it off the heat
dump in the flour, baking soda and salt and begin whisking
Then add sour cream, egg and vanilla mixture and whisk to combine it all
Pour into prepared pan and even out as best you can and place in the oven.
It takes about 12-14 minutes and I rotate the pan half way to prevent one side from being higher. Let cool.