Preheat oven to 180°C (conventional bake). Sift the first measure of cocoa into a small bowl. Stir in sugar. Set aside
Drain Wattie’s Black Doris Plums and reserve the syrup. You will need 1 ¼ cups of syrup. Remove the stones from the plums. Place the plums in the bottom of a greased deep sided 18-20cm diameter ovenproof dish (A soufflé dish is perfect).
Sift flour, baking powder and second measure of cocoa into a mixing bowl. Stir in the brown sugar. Whisk egg and milk together and pour into the dry ingredients with the melted butter. Fold ingredients together to mix. Spoon batter over plums. Smooth the top with the back of the spoon. Sprinkle top with prepared sugar and cocoa.
Heat the plum syrup until boiling. Carefully pour over the batter. Bake for 35-40 minutes until the pudding springs back when gently pressed in the centre. Serve hot with cream or Greek Yoghurt if wished.