Preheat oven to 350° Grease and line with wax paper 2 9 inch round pans. Blend hot coffee, sour cream and oil with a whisk, set aside. Mix in bowl sugar, flour, soda and salt. Add coffee mixture slowly until mixed. Add eggs one at a time until blended. Add chocolate. Pour in pans (batter will be runny) and bake for 35-45 minutes. Remove from pan and cool completely. Prepare icing in blender only. Blend milk and sugar on high speed for 2 seconds. Add chocolate and mix at high speed for 1 1/2 minutes or until blender sound changes. Let set room temperature for 30 minutes then cover and set another hour. This helps the xture to become more spreadable. Frost cooled cake.