Old-Fashioned Chocolate Cake

Last weekend I made what I shamelessly refer to as the best cake I have ever made. Much credit is owed to the recipe, which is concise, easy to follow, and to be honest, it's hard to believe that it's so simple when comparing it to the quality of the result.
I have made this cake once before for a close friend's birthday, and it turned out absolutely delicious. I was a tad wary of using sour cream in a cake the first time I made it, but it made the cake incredibly moist and the batter itself was so delicious that my sister offered to wash up just so she could eat the leftover clinging to the  (whatever you call the detachable thing you use for a  food processor).
This time, it was made for Mother's Day (see post below), and only had to be shared amongst the five immediate members of my family, and my mum even ate a few slices without complaining about how much fat and sugar was in it.
I find that putting chocolate cake in the microwave for fifteen seconds or so is similar to toasting a sandwich, it just adds an extra level of deliciousness. This proved true for this cake, and I strongly recommend this to anyone who attempts this cake.
So here's the recipe, if you like your cakes on the simple and delicious side, do try it!

(Adapted from Nigella Lawson's Old-Fashioned Chocolate Cake recipe)

For the cake: 

• 200g plain flour
• 200g caster sugar
• 1 tsp baking powder
• 1/2 tsp baking soda
• 40g cocoa
• 175g soft unsalted butter
• 2 large eggs
• 2 tsp vanilla essence (use extract if you have it)
• 150 mL sour cream

For the ganache: 

• 75g unsalted butter
•  175g dark chocolate, broken into pieces
•  300g icing sugar
• 125mL sour cream
• 1 tsp vanilla essence

1.  Preheat oven to 180 degrees and grease a 20cm cake tin.
2. Put everything into a food processor and blitz until you have a smooth, thick batter. (Seriously, that's it. I usually get scared that the batter is too thick, so i splash in a bit of milk while I'm blitzing it).
3.  Bake for around 30 minutes or when until a skewer comes out clean. (For me, both times, most of it was cooked but the centre was stil gooey; make sure all of it is completely cooked before removing it, but also take care not to leave it in the oven for too long or the rest of it will dry out).
4. Allow cake to cool for five minutes in its tin before transferring to a wire rack to cool completely.
5. When  cake is completely cool, prepare the ganache. Melt the chocolate and butter together by placing them in a bowl over a pot of barely simmering water, stirring occasionally.
6. When the mixture has finished melting, sift the icing sugar  into a small bowl while the chocolate mixture cools. Add the sour cream and vanilla and then the icing sugar into the chocolate mixture, whisking while the icing sugar is added to prouduce a silky smooth concoction.
7. Cover cake in the icing and.....eat it.

 Note: The quantities will probably make more icing than you need, it will thicken upon refrigeration into a solid mousse-like mass, but can be used again if heated slowly in the microwave (or y'know, just grab a spoon and eat it in its solid form).