Preheat the oven to 160oC/325oF/Gas
3. Line a 33 x 23cm baking tin with greaseproof paper and grease the
paper.
Sift together the flour, baking powder
and spices. Place the raisins in another bowl and toss with a few
tablespoons of the flour mixture.
With an electric mixer, cream the
butter or margarine and sugar together until light and fluffy. Beat in
the eggs, one at a time, then the black treacle.
Stir in the flour mixture, raisins and
walnuts.
Spread evenly in the baking tin.
Bake until just set, about 15-18
minutes. Cool in the tin before cutting into bars.