1. Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).
2. Melt the chocolate and margarine in a saucepan over a low heat and allow to cool.
3. Beat eggs and sugar for three minutes. Carefully add the chocolate mixture. Fold in the flour and baking powder and mix well. Pour into a lined 9×13-inch (23×33-centimeter) baking pan and bake for 30 minutes. The brownies should be a bit moist. Allow to cool.
4. Melt the white chocolate in a microwave and add the caramel. Mix well and pour over the cooled brownies.
5. Freeze and cut into rectangles or any other desired shape.