Seems a little low to me, especially since it's the only ingredient that
is going to make the bread rise. I think mine has a Tablespoon. Maybe a typo?
Here's my favorite:
3 cups all-purpose flour
1/2 cup sugar
1 Tablespoon baking powder
1 teaspoon baking soda
1/2 teaspoon salt
4 tablespoons unsalted butter
1 cup raisins (I used a mixture of dried
fruit, soaked for 10 minutes)
1 cup buttermilk (I used regular milk)
1 egg
optional: caraway seeds
Set a rack in the middle level of the oven
and preheat to 400 degrees.
In a mixing bowl, combine the flour, sugar,
baking powder, soda and salt and stir well
to mix. Add the butter and rub in until the
butter disappears into the dry ingredients.
Stir in the caraway seeds if used and the
raisins.
In a small bowl, whisk the buttermilk and
egg together and mix into the dough mixture
with a rubber spatula.
Turn the dough out on a floured work surface
and fold it over on itself several times,
shaping it into a round loaf. Transfer the
loaf to one cookie sheet and cut a
cross in the top. Bake for about 30 to 40
minutes, until well colored and a toothpick
plunged into the center emerges clean.
Cool the soda bread on a rack and serve with
plenty of sweet butter and bitter orange
marmalade.