Preheat oven to 350 degrees F (175 degrees C). Grease two 9 inch, round cake pans, and line with parchment paper.
Combine 2 1/2 cups flour, salt, and spices.
Dissolve soda in buttermilk: stir well.
Cream butter or margarine. Gradually add sugar, beating well. Add eggs, one at a time, beating well after each addition. Mix flour mixture into creamed mixture alternately with buttermilk mixture, beginning and ending with flour mixture. Dredge dates and pecans in remaining 1/2 cup flour, and fold into batter. Carefully fold grape jam into batter. Pour batter into prepared pans.
Bake for 40 to 45 minutes, or until a wooden toothpick inserted in center comes out clean. Cool in pans for 10 minutes. Remove layers from pans, and cool completely.
Spread hot Kentucky Fruit Filling between the layers and on top of the cake.