Preheat oven to 350°. In a large bowl, combine flour, 1-1/2 cups sugar, soda and salt. In a small bowl, whisk eggs, buttermilk and oil. Stir into dry ingredients just until moistened. Fold in raisins. Combine cinnamon and remaining sugar; set aside.
Spoon half the batter into two greased 8×4-in. loaf pans. Sprinkle with half of the reserved cinnamon sugar; repeat layers. Cut through batter with a knife to swirl.
Bake 55-60 minutes or until a toothpick inserted in center comes out clean. Cool 10 minutes before removing from pans to wire racks. Freeze option: Wrap cooled bread in foil and freeze for up to 3 months. To use, thaw at room temperature.