Lightly grease a 23cm/9in
square shallow tin and line with
baking parchment, leaving the paper
hanging over on 2 opposite sides.
Place the pastry on a baking tray
lined with baking parchment. Prick
the pastry allover with a fork and
bake for 15 minutes, or until
golden.
Ease into the tin, trimming
the edges if necessary. Reduce the
oven heat to 180°C/350°F/Gas mark 4.
Cream the butter and sugar in
a small bowl with an electric beater
until light and fluffy. Gradually
add the egg, beating after each
addition, then the lemon zest.
Fold
in the almonds and flour, then
spread the mixture over the pastry.
Scatter the raspberries and
blackberries on top and bake for 1
hour, or until
lightly golden. Cut into pieces and
dust with icing sugar to serve.