here's the scoop, right from the source:
1/2 cup cornstarch
1/2 cup icing sugar
1 cup rice flour
1/2 cup butter ( another 1/4 cup can be added if you feel the batter is too dry)
blend together, form into little balls and bake at 300 for 20- 25 minutes, until golden around the edges.
*rogers icing sugar is safe
*bob's red mill cornstarch is safe