Preheat oven to 350 degrees. Grease and flour four 8-inch or 9-inch cake pans, or line them with parchment paper. Combine buttermilk and baking soda; set aside. Sift together flour, salt, and spices; set aside.
Cream butter, sugar, and vanilla until light and fluffy. Add the eggs one at a time, beating well and scraping the bowl after each addition. To the butter mixture, add half the flour mixture and mix until combined. Add half the buttermilk mixture and mix until combined. Add the rest of the flour mixture and mix; then add the rest of the buttermilk and mix. Scrape the bowl and mix well.
Add raisins, nuts, and jam; mix well. Pour into prepared pans. Bake 25 to 30 minutes, until a tester inserted in the center comes out clean. Place pans on wire racks to cool.
This recipe from CDKitchen for 100-Year Old Jam Cake serves/makes 8