3/4 cup icing sugar
1 cup cornflour
1 cup plain flour
1/2 teaspoon baking powder
Now all you have to do is, cream the butter and icing sugar together, then add the cornflour, plain flour, and the baking powder into the mixture and combine.
When the flour is being mixed in, it will seem a little clumpy, but keep mixing and it will come back together.
Roll the dough into little balls, squish with a fork, and bake for 20 minutes at 180C.