Preheat oven to 350°. In a large bowl, combine first five ingredients. Stir in raisins. Set aside 1 tablespoon beaten egg. In a bowl, combine buttermilk, oil and remaining eggs; stir into flour mixture just until moistened (dough will be sticky). Transfer to a greased 9-in. round baking pan; brush top with reserved egg.
Bake 45-50 minutes or until a toothpick inserted in the centre comes out clean. Cool 10 minutes before removing from pan to a wire rack to cool. Cut into wedges.