500g sweetened chestnut purée (from delicatessens)
50g (½ cup) drinking chocolate
¼ cup brown sugar
75g almond meal (ground almonds)
6 sprigs fresh rosemary, leaves roughly chopped, plus extra sprigs to decorate
icing sugar, for dusting
Preheat the oven to 180ºC.
Grease and line a 18-20 cm round cake tin with baking paper.
Separate the egg whites and yolks.
Using a mixer, whisk the egg whites until stiff, then set to one side. Pour the chestnut purée into a large bowl, lightly beat the egg yolks with a fork in a separate bowl, then stir into the purée.
Add the ground almonds, sugar and drinking chocolate, and stir until well combined. Add the rosemary leaves and stir until well combined.
Gently fold the egg whites into the batter, then pour into the prepared tin and sprinkle a few extra rosemary sprigs on top.
Bake for 40–45 minutes or until a skewer inserted into the middle comes out clean. Leave to cool in the tin, then turn out and dust with icing sugar to serve.