Magnolia Kitchen signature chocolate cake with dark chocolate ganache

Name: Magnolia Kitchen signature chocolate cake with dark chocolate ganache
Prep time: 20 min
Cook time: 28 h 15 min
Total time: 28 h 15 min
Yield: 18 slices
Ingredients: 150 g pouring (whipping) cream; 600 g dark chocolate (50% cocoa); 185 g salted butter; 275 g plain flour; 450 g brown sugar; 90 g Dutch cocoa powder; 2 tsp bicarbonate of soda; 280 g warm water; 90 g canola oil; 1 ½ tsp instant coffee; 3 eggs; 1 ½ tsp natural vanilla extract; 195 g buttermilk