Preheat the oven to 350°F. Generously butter a 12 inch diameter cast iron (ovenproof) skillet with 2 inch-high sides.
Place first 5 ingredients (dry) into a large bowl; whisk to blend. Add butter, using pastry cutter (or fingers) to rub in until coarse crumbs form. Add raisins and caraway seeds and stir.
Whisk together buttermilk and egg in a medium bowl. Add to dry mixture using rubber spatula, and stir just until blended. The dough will be wet and sticky.
Pour the dough into the prepared skillet; smooth the top and mound slightly in the center. Dip a knife in flour and make a 1-inch deep criss-cross in the center.
Bake for approximately 65 to 75 minutes or until toothpick inserted in center comes out clean. Cool bread in skillet for 15 minutes. Turn out on rack and cool completely.
Notes
his bread may be prepared one day ahead. Wrap tightly in foil or an extra large ziploc; store at room temperature.