Orange Chocolate Cake

Ingredients

• 7/8 cup butter
• 1 1/2 cups caster sugar
• 3 large eggs
• 1 tablespoon orange rind
• 4 tablespoons orange juice fresh
• 1 teaspoon vanilla extract
• 2 cups plain flour
• 1 teaspoon baking powder
• 1 teaspoon baking soda
• 1/8 teaspoon salt
• 7/8 cup sour cream or plain natural yoghurt
• 2 7/8 tablespoons semi sweet chocolate chop to pieces and melt in microwave or double boiler