Preheat the oven to 180°C, butter and line the bottom of 2-20cm or 2-8 inch spring form pans.
Let the butter soften to room temp. Let the eggs stand out as well.
Place all the dry ingredients into the bowl of a food processor or stand mixer. Pulse once or twice to mix it all together.
In a small bowl mix all the wet ingredients.
Turn on the mixer and pour the wet ingredients in to the dry. Mix just until everything is combined into a nice thick batter.
Divide equally between 2, 20cm or 8 inch spring form pans that have been buttered and have the bottoms lined with a layer of baking parchment.
Bake on a rack placed in the middle of a preheated oven at 180°C for about 35 minutes. See notes below.
Let cool for 10 minutes and then remove from the pans and let them come to room temp before icing.
For the icing
Break up the chocolate and melt with the butter over hot water.
Sieve the powdered sugar which will remove any lumps.
When the chocolate and butter are melted add the syrup and vanilla extract. With a whisk, whisk in the powdered sugar. Mix well to incorporate everything together. Let cool for a few minutes and it should be ready for icing the cake.
If the icing is too thick add a spoon full of hot water to thin it a bit. If it is too thin, add a spoonful more of the powdered sugar until you get a good icing consultancy.
Notes
[recipe]I like to test for doneness with with a toothpick. I begin testing at 25 minutes because I like it to be done but still a little moist in the center. Stick the toothpick into the center of the cake and you should see a bit of chocolate cake still stuck to it. It should be cake not batter that sticks to it. It will then have the consistency of something like a brownie - a bit dense. If it cooks a bit more it's no disaster, its just a great tasting chocolate layer cake.Try this recipe it could become your families regular for a great reliable, easily made chocolate cake.I have also frozen these for a month or two and then taken them up to the country house for a weekend treat.