Step 1

Grease a 10-12 cup capacity bundt cake pan really well with butter. Preheat oven to 180 C (350 F) standard / 160 C (320 F) fan-forced.

Step 2

In a large mixing bowl, add butter and sugars and beat with an electric mixer until pale and creamy.

Step 3

Add vanilla and eggs, one at a time, and continue to beat until mixture is combined and creamy. Boil the kettle and pour out 1/2 cup water and set aside.

Step 4

In a separate bowl, sift plain flour, cocoa powder, baking powder and baking soda and lightly whisk.

Step 5

Add dry ingredients to the wet, along with the hot water and gently fold with a spatula. Finally, add the sour cream and  fold until the mixture is completely combined and smooth. It will be quite thick – this is fine.

Step 6

Pour chocolate batter into prepared bundt pan and bake for approximately 40 minutes or until a skewer inserted into the middle of the cake comes out clean. Leave the cake to cool for about 15 minutes before carefully transferring to a wire rack to cool completely.

Step 7

To make chocolate ganache, chop dark chocolate and transfer to a bowl. In a small saucepan, add your cream and pop on a medium heat. Once the cream is warm but not boiling, pour the cream over the chocolate and leave for 2-3 minutes.

Step 8

Gently whisk the mixture until smooth. Leave to stand for a few minutes and it will thicken slightly. Then pour chocolate ganache over the top of your cake.