1. Cream the butter and sugar until light and fluffy. Then add the eggs one at a time beating after each addition. Sift in the flour and baking powder and stir through. Pour in the orange juice and zest, and lightly beat together on last time.
2. Grease a glass or stainless steel bowl with butter, and place the fresh berries on the bottom, holding back ¼ of them for dressing the pudding once cooked. Pour the pudding batter over the fresh berries. Take a piece of tin foil and a piece of baking paper sized to fit over the top of the bowl. Place the foil and paper over the pudding and tie in place with a piece of string. Transfer the pudding bowl to a saucepan that is filled 2/3 of the way with boiling water. Reduce the heat to simmer and leave to cook for 2 ½ hours. Continue to top up the water with hot water from the kettle as the pudding cooks – probably once or twice.
3. Once the pudding has cooked, remove from the saucepan, and transfer to a serving plate or cake stand. Serve warm or cold with softly whipped cream, and fresh berries.