For the blueberry and curd cake, cream sugar and margarine until fluffy. Gradually beat in the eggs. Mix flour with the baking powder and stir into the mixture.
Spread the batter evenly on a high baking sheet. For the icing, mix curd cheese with whipped cream until smooth. Add the pudding powder, sugar, lemon juice and lemon zest.
Spread the icing evenly on the dough. Spread the blackberries evenly over the icing. Bake at 180 °C top/bottom heat for about 45 minutes.
Let cool and serve cut into pieces. Sprinkle with powdered sugar if desired.