Preheat oven to 325.
Grease a 9x5 loaf pan and dust lightly with flour.
1 cup butter
Gradually beat in
1 cup fruit sugar (superfine sugar)
Beat until very light and fluffy.
One at a time, beat in
Beat for 2 minutes after each egg.
1 tsp vanilla
Blend or sift together
1 1/2 cups All-Purpose flour
1/2 tsp cream of tartar
1/4 tsp salt
Gradually add the dry ingredients to the egg mixture, folding in well. Then beat for 2 minutes (at low speed with electric mixer).
Turn into prepared pan.
Bake in preheated 325 degree oven for 60 to 70 minutes.