Preheat oven to 350 degrees | Line three 9-inch cake pans with parchment paper
- In a large bowl, cream butter and brown sugar until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in vanilla.
- In another bowl, whisk flour, cocoa, baking soda, and salt; add to creamed mixture alternately with sour cream, beating well after each addition. Carefully, stir in water until blended.
- Evenly pour cake batter between each cake pan. Bake for 30-35 minutes or until a toothpick inserted in the center comes out clean.
- Cool in pans 10 minutes before removing to wire racks to cool completely.
- In a large microwave-safe bowl, add butter and chocolates. Microwave in 15-second intervals until stir between every 15 seconds until smooth. Cool slightly.
- Add confectioners' sugar, sour cream, salt, and vanilla to the chocolate mixture and beat until smooth.
- Spread frosting between layers and over top and sides of cake. Refrigerate leftovers.
You can bake the cake in a 9-by-13 cake pan as well.
You can sub out hot coffee for the hot water for an espresso-chocolate cake!