Cream butter in a large mixing bowl; gradually add sugar, beating until light and fluffy. Add eggs, one at a time, beating well after each addition.
Dissolve soda in buttermilk. Combine flour, cocoa, and spices; add to creamed mixture alternately with buttermilk mixture, beginning and ending with flour mixture. Add jam and vanilla, mixing well. Fold in raisins and pecans.
Pour batter into 3 waxed paper-lined, greased and floured 9-inch round cake pans. Bake at 350° for 30 minutes or until a wooden pick inserted in center comes out clean.
Cool in pans 10 minutes. Remove layers from pans to wire racks, and cool completely. Spread frosting between layers and on top and sides of cake.