Step 1 Preheat the oven to 180C° . Grease and line a 20cm round spring-form cake tin with butter and non-stick baking paper. Step 2 In a small saucepan, melt the chocolate and butter over a low heat, mixing really well to combine. Once completely melted set aside to cool. Step 3 Sift the self-raising flour and cocoa powder into a large bowl. Add the caster sugar and stir to combine. Create a well in the centre of the dry ingredients and crack in the eggs, then add in the milk, vanilla extract and melted butter-chocolate combination. Whisk together until smooth then pour in the wet ingredients and mix until just combined. Step 4 Spoon the batter into the cake tin, smoothing the surface with a spatula and bake for 40 minutes. you will know the cake is ready when a skewer is inserted into the centre of the cake, and it comes out clean or with a few crumbs sticking to it. Step 5 Allow the cake to cool in the tin for 10 minutes before turning out onto a wire rack to cool completely. For The Ganache Icing Step 6 In a small saucepan over low heat, melt the chocolate and set aside to cool. In a medium bowl, add the sour cream and melted chocolate and mix to combine. Put the ganache in the fridge for at least 10 minutes to firm up to a thick spreadable consistency. Step 7 Once the cake is completely cool, place on a plate or cake stand and using a spatula or a butter knife, spread the ganache evenly over the top of the cake. Start from the center and work your way outward, smoothing the ganache as you go. Finally, spread a thin layer of ganache around the sides of the cake so it is covered completely.
