Preheat the oven
to 180"C/350"F /Gas 4. Using greaseproof paper, line
a 25 X 5cm/l0 x 2in tin and grease the paper. For
the topping, combine the flour, light brown sugar
and cinnamon in a bowl. Add the butter and rub in
until it resembles coarse breadcrumbs.
Cream the butter
or margarine and sugar until light and fluffy. Beat
in the eggs, one at a time. Stir in the vanilla. In
three batches, sift, then fold in the flour and
baking powder.
Pour the mixture
into the tin. Arrange the plums on top and sprinkle
with the topping.
Bake until a
skewer inserted in the centre comes out clean, about
45 minutes. Cool in the tin.
To serve, run a
knife around the inside edge and invert on to a
plate. Invert again on to a serving plate so the
topping is uppermost.