Preheat the
oven to 375°F/190°C/gas 5. Butter two cookie
sheets.
Sift the
flour, baking powder and salt into a medium
bowl. Beat the butter and sugar in a large bowl
with an electric mixer at high speed until
creamy.
Add the egg
and vanilla, beating until just blended. Mix in
the dry ingredients, followed by the raisins and
orange zest.
Drop
tablespoons of the dough 2 inch (5cm) apart onto
the prepared cookie sheets.
Bake for
12-15 minutes, or until just golden. Cool on the
sheets until the cookies firm slightly. Transfer
to racks to finish cooling.