1
Combine the butter, water, cocoa powder, and salt over heat. Cook until melted then set aside. Whisk together the flour, sugar, and baking soda separately. Add half of the melted butter cocoa mixture and whisk. Then, add the remaining mixture and stir.
2
Add the eggs, sour cream, and vanilla extract and whisk. Then, pour the cake batter into a prepared pan. Bake and let cool.
3
Finally, make the frosting and spread it over the cake.