Sift unbleached white flour, baking soda & baking powder into a blow. Add raisins to flour mixture & then slowly add 3 cups of shaken buttermilk to the dry mixture. Mix gently & dust a working surface with flour.
Pour soda bread mixture onto flour, sprinkle flour on top & toss gently. Place on a lightly sprayed pan. Lightly cut a cross on top of dough.
Bake at 350° for 30 minutes. Rotate pan 180° & bake for another 30 minutes.
Remove bread from pan & place on a wire rack. Dust top of bread with flour. Cover with a tea towel. Let bread cool serval hours.