Cream butter and sugar together until light and fluffy.
Gradually add beaten eggs, beating the mixture well between each addition.
Fold in sieved flour and baking powder.
Spoon into greased and lined 9"round tin. Bake at 180 degrees C for about 25 minutes or until golden in color. Remove from oven.
Cool slightly before turning out.
When cool, split in half and fill with jam and cream.
To make Jam:
Roughly chop plums and place them in a large pan with the rind, juice and water.
Bring to a boil and simmer for 15 minutes.
Add sugar, while on the heat.
Dissolve the sugar.
Bring to a fast boil and cook until setting point is reached.
Leave to cool and use to fill the cake.
Key Ingredients: butter, castor sugar, egg, all purpose flour, baking powder, plum, lemon, lemon juice, lemon rind, sugar, cream