I am totally indebted to Darina for this recipe. I sometimes make this with peaches or nectarines too. It is such a great pudding for a dinner party of any sort and if there is any left over, it will keep for days, great with a cup of coffee.
Stir over a medium heat until the sugar dissolves, then cook without stirring until the sugar caramelises to a golden brown.
Meanwhile half and stone the plums, carefully arrange cut side down in a single layer over the caramel (this will be the top of the cake when it is cooked).
Put the butter, sugar and flour into the bowl of an electric food processor, whiz for a couple of seconds, then add the eggs and stop as soon as the mixture comes together. ( if you don’t have a food processor, just cream the butter and sugar, add the eggs one by one, then mix in the flour).
Spread the mixture in an even layer over the plums in the pan.
Bake in the preheated oven for about one hour.
The centre should be firm to the touch and the edges slightly shrunk from the sides of the pan.
Run a knife around the edges to make sure it has not stuck anywhere.
Do leave it to sit for 3 or 4 minutes before turning out.