Heat oven to 350 F. Grease a large cast-iron skillet or baking sheet.
In a large bowl, mix 4 cups flour with the baking powder, baking soda, salt, sugar and caraway seeds. Add raisins**, making sure they are separated. Add buttermilk* to bowl and stir with a wooden spoon until mixture forms a dough.
Sprinkle about 1/4 cup of remaining flour on a board. Turn out dough and knead lightly for about 5 minutes, working in the flour from the board and forming dough into a smooth, round loaf about 8-inches in diameter. Press loaf evenly into pan or on baking sheet and cut a cross 1/2-inch deep in the top.
Bake 1 hour and 15 minutes or until loaf sounds hollow when tapped on the bottom. Put loaf on wire rack, rub top with butter and sprinkle with sugar.