Preheat the oven to 350. Generously butter 2 (9 by 5-inch) bread pans.
Stir together the sifted flour, sugar, baking powder, salt, and baking soda. Cut in the butter and mix very thoroughly with your hands until it gets grainy. Stir in raisins.
Add the buttermilk and egg to the flour mixture. Stir until well moistened. Shape dough into 2 loaves and place in the pans.
Bake for 1 hour. Test with a toothpick for doneness. Cool in the pans for 3 to 5 minutes. Transfer to a wire rack to cool.