BREAD: In large bowl, combine flour, salt and baking soda. With pastry blender or two knives, cut in butter until mixture resembles coarse crumbs. Stir in raisins or currants (if using). In separate bowl, combine buttermilk, honey and whisky. Add all at once to dry ingredients; stir just until no dry spots remain. Turn dough out onto lightly floured surface. Knead lightly 1 minute (too much handling will toughen loaves, while too little will inhibit rising.) Divide dough in half and shape each half into an 8 in (20 cm) round. Place in two greased 8 in (1.2 L) round cake pans. With floured knife, cut a cross 1/2 in deep in each loaf.
GLAZE: In small bowl, combine whisky and milk. Brush loaves with glaze. Bake in 350F (180C) oven 35 to 40 minutes or until loaves sound hollow when tapped on bottoms. Remove from pans; let cool on wire racks. Cut into wedges.