• Preheat the oven to 350℉. Set the rack at the center of the oven shelf.
• Sift the flour, cocoa powder, sugar, baking powder, baking soda and salt in a large mixing bowl then stir to mix.
  
• In another bowl or large measuring cup, add the hot water, butter and vanilla. Let it sit for a few minutes for the butter to melt. Add the eggs and whisk to combine.
  
• Pour the egg mixture into the flour mixture then whisk until smooth. Add the sour cream and then gently whisk to combine. Avoid overmixing.
  
• Pour into the prepared baking pan and bake for 35 minutes or when a tester comes out moist but clean.
  
• Let it cool in the pan for 10 minutes to handle before turning it out into the cake stand. Let it cool completely.
  

Make the Ganache

• Pour the whipping cream in a small saucepan and place over medium-low heat. Once the bubble starts to appear for about 3 -5 minutes, add the chocolate. Remove the pan from the heat and let it sit for at least 5 minutes for the chocolate to melt. Whisk until smooth. It will thicken as it cools but make sure that it is pourable.
  

Assembly

• Confidently pour the ganache starting at the center of the cake. Let it flow all the way to the sides. Scrape the ganache that flows into the cake stand using an angled icing spatula back to the cake or use it to glaze the sides immediately before the ganache will get thick.
  
• Once the cake is set, decorate your cake with any garnish of your choice. Let the cake sit for at least an hour at room temperature or 30 minutes in the fridge before cutting. Cake can last at room temperature covered for up to 3 days and up to 5 days in the fridge.