Preheat the oven to 180°C/160°C fan forced.

Position an oven shelf towards the center of the oven. Line the base of the Le Creuset Cast Iron Heart Casserole with baking paper and grease the paper and sides of the casserole with spreadable butter.

Sift the flour, cocoa powder, baking powder and salt into a mixing bowl. Add the caster sugar, spreadable butter, unbeaten eggs, Greek yogurt, rosewater, and vanilla extract. Use a wooden spoon to beat the mixture together for 1 - 2 minutes until smooth and creamy. Fold in the raspberries, squashing them down a little. Spoon the mixture into the prepared casserole and level the top.

Bake for 45 - 50 minutes. To test the cake is cooked, insert a fine skewer into the center of the cake, it should come out clean, if not then cook for a further 3 - 5 minutes more. Place the casserole on a wire rack and leave until the cake has cooled completely.

To decorate the cake, melt the chocolate in a heatproof bowl placed over a saucepan of gently simmering water, make sure the water does not touch the base of the bowl. Drizzle over the cake and sprinkle a few raspberries on top. Just before serving, scatter a few pink rose petals over the surface and dust with a little icing sugar.

Cook's Notes:Cut the cake using a plastic knife so that you avoid scratching the enamel surface. Alternatively, ease the cake from the casserole by running a plastic or rubber spatula around the sides.