Cream together the butter, sugar and vanilla seeds until light and fluffy.
Sift the flour and semolina together, then gradually work the into the creamed butter mixture to make a dough.
Gently knead the dough on a lightly floured surface until smooth. Roll out quite thinly and prick all over with a fork. Using a 7cm fluted cutter, cut out 12 rounds. Place these on a baking sheet and chill for 30 minutes.
Meanwhile, make the filling. Whisk together the cream with the icing sugar until soft peaks form. Fold in the rose water and chill until required.
Preheat the oven to 180 C / Gas 4. To make the decoration, paint the roses and leaves with the egg white. Dust with sugar; dry on a wire rack.
Bake the shortcakes for 15 minutes or until lightly golden. Lift them off the baking sheet with a metal spatula and cool on a wire rack.
To assemble: Spoon the rose water cream onto half the shortcakes. Add a layer of raspberries, then top with second shortcake. Dust with icing sugar. Decorate with dusted roses and mint sprigs.