I don't know how authentic this recipe is and I make individual ones instead of one big loaf, but we really like it and look forward to having soda bread every St. Patrick's Day!
2 cups flour
1 tsp baking powder
1/2 tsp baking soda
2 Tbsp brown sugar
3 Tbsp butter
1 beaten egg
3/4 cup buttermilk or sour milk
1/3 cup raisins or currents
Combine dry ingredients in a large bowl. Cut in butter. Add milk and egg. Stir just until moistened. Stir in raisins or currents.
Drop onto greased baking sheet and bake at 375 about 15-20 minutes or until golden brown.