1. Preheat oven to 160°C. Line a 23cm cake tin with baking paper. Put chocolate and 75g of the butter in a small saucepan and cook over a low heat until melted. Set aside to cool.
2. Put remaining butter and caster sugar in the bowl of an electric mixer and beat for 5 minutes or until light and creamy. Add eggs, 1 at a time, beating well after each addition. Add vanilla and beat to combine.
3. Put cocoa and water in a small bowl and stir until dissolved. Sift flour, baking powder and bicarb into a medium bowl. Fold into butter mixture with almond meal and cocoa mixture. Spoon into prepared tin and bake for 1 hour and 5 minutes or until cooked when tested with a skewer. Cool in tin for 5 minutes, then turn out onto a wire rack to cool completely.
4. Dust cake with icing sugar and top with berries to serve.
Raw caster sugar gives this cake a richer caramel flavour, but you can use the regular variety instead.