1. Preheat oven to 180°C. Grease a 6-inch springform cake tin with a little butter.

2. Mix together the almond meal, demerara sugar, brown sugar and salt, then rub in with the butter by hand until the mixture resembles breadcrumbs. Divide the mixture in two and press half of the mixture into the base of the tin.

3. In a metal mixing bowl placed over a saucepan of boiling water, melt the chocolate and 100ml of the cream until smooth. Remove from the heat and with a wooden spoon beat in the egg, half the yoghurt, the remaining almond/base mix and the cinnamon and nutmeg until the batter is smooth.

4. Pour the batter over the base and scatter the chopped pistachios in a ring around the edge of the tin.

5. Bake the cake for 45 minutes; the batter should be cooked through but still mousse-like in the centre. Allow to cool in the pan.

6. Lightly whip remaining cream and fold through the remaining yoghurt.

Serve cake with the cream mixture and the Persian fairy floss and dried rose petals, if using.