1. Preheat the oven to 180C.
2. Cream the butter and sugar together until pale and creamy. Then gradually add the eggs, beating well in between adding each egg.
3. Mix in the vanilla extract and then slowly fold in the flour.
4. Scrape the batter into a 24cm baking dish that has been lightly greased, and scatter the plums on top.
5. Bake for about 40 minutes, or until golden and springy to the touch.
6. Serve with custard or cream.
Make sure your sponge is perfect every time with one of our 60cm range cookers.