Preheat oven to 350F.

In a medium bowl, combine the flour, sugar and spices.

Cut in the butter until the mixture resembles corn meal.

Reserve 1/2 cup of the mixture.

In a second bowl, combine the buttermilk and baking soda.

Pour this into the remaining crumb mixture in halves, beating thoroughly after each addition.

Stir in the raisins and nuts.

Spread the batter into a greased and floured 9 x 13 inch pan.

Sprinkle reserved crumb mixture over the top.

Bake at 350F for 1 hour until brown and springy when touched or until a toothpick inserted into the cake comes out clean.