chocolate cake with whipped chocolate frosting
1 1/2 cups cocoa
1 1/2 cups boiling water
500g butter, softened
4 1/2 cups caster sugar
2 teaspoon vanilla extract
4 cups self raising flour
1 cup plain flour
1 teaspoon bicarbonate of soda
2 1/2 cups buttermilk
WHIPPED CHOCOLATE FROSTING
300g dark chocolate, chopped
200g milk chocolate, chopped
180g butter, chopped
2 teaspoons vegetable oil
Preheat the oven to moderately slow 160 degrees/140 degrees fan forced. Whisk the cocoa and boiling water in a medium bowl until smooth; allow to cool.
Grease a deep 30cm square cake pan. Line the base and sides with two layers of baking paper, extending the paper 5cm about the edge of the pan.
Bake the butter, sugar and vanilla in a bowl with an electric mixer until light and fluffy. Add eggs one at a time, beating until just combined between additions. Transfer butter mixture to a very large bowl.
Stir in combined sifted flour and soda, and the buttermilk in three batches until well combined. Stir in the cocoa mixture mix well. Spread mixture into the prepared pan and bake in a moderately slow oven for 1 1/2 hours or until cooked when tested. Cool cake in pan for 20 minutes turning onto a wire rack to cool.
WHIPPED CHOCOLATE FROSTING : Place both chocolate and butter in medium heatproof bowl; stir over a pan of simmering water until the chocolate and butter melts. Stir in the oil. Refrigerate chocolate mixture until thick. Beat chocolate mixture with an electric mixer for about 3 minutes.
Spread whipped chocolate frosting over the top and sides of the cooled cake.