Combine chocolate, butter and milk in a medium sized saucepan. Melt ingredients over a low heat, stirring continuously. Remove from heat and quickly whisk in Edgell Instant Mash. Allow to cool.
Mix together egg yolks, brandy, vanilla essence and stir into cooled chocolate mixture. Beat egg whites until stiff peak form. Gradually add brown sugar beating well between each addition, until thick and glossy. Fold half the egg white mixture into the chocolate mixture. Repeat with remaining egg white mixture.
Pour mixture into a baking paper base lined 20cm greased springform pan. Bake in a preheated oven at 180°C for 25-30 minutes. Cool in pan. Serve sprinkled with icing sugar.