01 -
Preheat oven to 175°C. Grease and line two 20 cm round cake pans with parchment paper.
02 -
In a large bowl, whisk together flour, cocoa powder, granulated sugar, brown sugar, baking powder, baking soda, and salt.
03 -
In a separate bowl, beat eggs, buttermilk, orange juice, vegetable oil, vanilla extract, and orange zest until combined.
04 -
Gradually mix the wet ingredients into the dry ingredients. Stir in hot water last until the batter is smooth.
05 -
Divide batter evenly between pans. Bake for 30 to 35 minutes or until a toothpick inserted in the center comes out clean. Cool layers completely.
06 -
Heat heavy cream in a saucepan until just simmering. Pour over chopped chocolate and let sit for 2 minutes. Stir in butter and orange zest until smooth and glossy.
07 -
Level cake tops if needed. Place one layer on a serving plate, spread ganache over it, then top with second layer. Pour remaining ganache over top, letting it drip down sides.
08 -
Allow ganache to set at room temperature for at least 30 minutes or refrigerate for a firmer texture.