Combine sugar, cornstarch, salt and spices. Blend in egg yolks. Add sour cream, raisins and lemon juice. Cook over moderate heat, stirring constantly, until mixture thickens. Cool. Stir in walnuts. Pour into pie shell. Top with meringue (see Perfect Meringue for Topping Pies).
Bake in moderate oven (350°F.) about 15 minutes, or until meringue is browned.