Plum and White Chocolate Dessert Cake

Ingredients

• 6-8 plums – halved and stone removed
• 3 tablespoons light butter or margarine
• 1/3 cup caster sugar plus extra tablespoon
• 1 teaspoon vanilla essence
• 1 egg
• 1/3 cup buttermilk
• 3/4 cup SR flour
• 100g white cooking chocolate – chopped
• Cream to serve
• Icing sugar for dusting