In a large bowl, combine the flour, sugar, salt, baking powder and baking soda. Cut in butter until mixture resembles coarse meal. Combine buttermilk and egg; stir into dry ingredients just until moistened. Stir in raisins and caraway seeds. Turn out onto a floured surface and knead lightly until smooth. Shape dough into a ball and place on a greased baking pan. Pat into a 7-in. round loaf. Cut a 4-inch cross about 1/4 inches deep on top to allow for expansion. Brush top with milk. Bake at 375° for 1 hour or until golden brown.