Shrewsbury biscuits

125g (4oz) butter, softened
50g (2oz) icing sugar
1 tsp vanilla essence
1 egg
1 1/2 cups flour
Pinch of salt
1 tsp baking powder
1/2 cup raspberry jam

Place butter, icing sugar and vanilla in a bowl and beat until thick and pale, then beat in egg.
Sift flour, salt and baking powder into the butter mixture and stir to combine.
Turn mixture out onto a board and knead lightly to bring together as a firm dough.
Wrap dough in plastic wrap and chill for 30 minutes.
On a lightly floured surface, roll out dough to 3mm thick. Cut out circles with a biscuit cutter and place on prepared baking trays. Cut out and remove smaller circles from the centre of half the biscuit circles.
Bake 180C for 15 to 20 minutes, then remove to a wire rack to cool. Sandwich biscuits together with raspberry jam and leave to set.