Preheat the oven to fan 220 degrees centigrade or gas mark 9.

Grease a 23cm-diameter flan dish with the coconut oil.

Blend all the ingredients together (apart from the plums) in a food processor or blender until smooth.

Pour the batter into the flan dish and arrange the plums cut-side-up on top. If you can't fit all the plums then just chop them up so that they fit.

Bake in the oven for 15 minutes until risen, golden and brown. Serve warm.