Ingredients
Method
1.Place chocolate, cocoa and soda in a medium bowl; pour boiling water over. Stand mixture for 2 minutes. Whisk chocolate mixture until smooth; refrigerate until lukewarm.
2.Meanwhile, preheat oven to 160°C (140°C fan-forced). Grease a 28cm round cake pan and line the base with baking paper.
3.Beat butter, sugar and vanilla in a large bowl with an electric mixer until light and fluffy. Beat in eggs, one at a time. Fold in half the cooled chocolate mixture, then combined sifted flours. Fold in remaining chocolate mixture, then the sour cream (do not overmix).
4.Pour mixture into the prepared pan; smooth the top. Bake for 1 hour 15 minutes or until cooked when tested. Cool cake in pan for 10 minutes before turning out onto a wire rack to cool.
5.To make sour cream frosting; combine chocolate and sour cream in a medium bowl. Gradually stir in icing sugar; mix until smooth and spreadable.
6.Split the cooled cake into 2 layers. Place bottom layer, cut-side up, on a serving plate. Spread with 1/3 of the sour cream frosting. Top with remaining cake layer. Spread top and sides with remaining frosting. Decorate with fresh flowers, if desired.