Step 1

Melt the chocolate in a double boiler or in the microwave in the bursts of 5 seconds so it doesn't get overheated. Stir till smooth and set aside. Peel the orange and remove as much of the white pith as you can, because it is bitter. Remove the seeds and blitz the orange in a food processor until smooth.

Step 2

Lightly grease a 9x5 loaf tin and line it with baking paper leaving a little overhang for easy removal. Preheat the oven to 175 C.

Step 3

Now sift the flour, cocoa, baking powder and salt in a large bowl.Set aside.

Step 4

In a mixing bowl, whisk the sugar and oil till combined, then whisk in the eggs one at a time, till completely combined.

Step 5

Now stir in the orange pulp and orange juice followed by the melted chocolate.

Step 6

Slowly fold in the flour mixture until you have a thick but smooth batter. If needed, run a hand mixer through it to break up any lumps.

Step 7

Spread the batter into the prepared baking tin and bake for 1 hour, then cover the top loosely with foil and bake for another 20 to 25 minutes until a toothpick poked in the center comes out clean. You can also bake this cake in a 9" round tin, and it should take about an hour to get done.

Step 8

Let the cake cool completely before you frost it.

Step 9

To make the ganache frosting, place the chocolate chisp in a bowl, and then combine the cream and orange zest in a saucepan over low heat. Stir and let the cream come to a very gentle simmer, not boiling. Pour the hot cream over the chocolate. Let it sit for a couple of minutes, then stir to make a smooth, silky ganache.

Step 10

Let the ganache cool and thicken at room temperature for about 30 minutes. If you're working in a warm kitchen, it's a good idea to chill the ganache for 10 minutes before you frost the cake.

Step 11

Spread the ganache on top of the cake and around the sides of it. If you're making a round cake and want to make two layers, you will need to make double the ganache.

Step 12

Let the cake chill in the fridge for 20 minutes to let the ganache set, though personally, I prefer it freshly frosted when the ganache is super soft! Slice and enjoy. The cake should be stored in the fridge at all times and will last about a week. Happy baking!