Irish soda bread (with variant for spotted dog)

6 c  All purpose flour
      2 ts Baking soda
      2 ts baking powder
      3 tb Cornstarch
      2 ts Sugar
      1 ts Salt
  2 1/2 c  buttermilk ***

----------------------------ADD FOR "SPOTTED DOG----------------------------
    1/2 c  Raisins or sultanas
 
  ***  may substitute 2 1/2 cup water and 10 tablespoons buttermilk powder.
  
  Preheat Oven to 375 degrees.
  
  Add all of the dry ingredients in a large bowl and mix very well.  (If
  making Spotted Dog variant, then add raisins.) Pour all of the buttermilk
  into the bowl at once and stir, using a wooden spoon, just until a soft
  dough is formed.  Do not try to make it smooth at this point.  Pour the
  contents of the bowl out onto a plastic counter and knead for a minute or
  so until everything comes together.  You may need to add a bit more flour
  depending on humidity.  The dough should be smooth, not sticky.
  
  Divide the dough into two portions and shape each into a round loaf,
  pressing the top down a bit to just barely flatten it.  Place the loaves on
  a large ungreased baking sheet.  Sprinkle some additional flour on the top
  of each loaf and, using a sharp paring knife, make the sign of the Cross in
  slashes on the top of each.
  
  Allow the loaves to rest for 10 minutes and then bake on the middle rack of
  the oven for 40 minutes, or until the loaves are golden brown and done to
  taste.
  
  Cool on racks.
  
  Adapted from: The Frugal Gourmet on Our Immigrant Ancestors, by Jeff Smith.
  Entered by Dale & Gail Shipp, Columbia Md. Personal comment: a close Irish
  friend gives her stamp of approval on this as being an authentic Irish soda
  bread.  She supplied the "Spotted Dog" variant.