1. Combine raisins and pineapple with juice in a bowl and soak several hours or overnight. Preheat oven to 350 degrees F. Sift flour and next 4 ingredients together in a bowl. Set aside.
2. Using an electric mixer, cream shortening and butter in a bowl. Gradually add sugar and beat until light and fluffy. Beat in eggs one at a time, beating well after each addition. Stir in jam and vanilla. Add half the flour mixture and half the buttermilk. Mix thoroughly. Add remaining flour mixture and buttermilk. Mix well. Stir in pineapple with juice, raisins and pecans.
3. Transfer to a buttered 9 x 13-inch baking pan. Bake for 55 to 60 minutes until a toothpick comes out clean when inserted in center.
4. Dust with confectioner's sugar before cutting into squares.