Preheat oven to 350 degrees F.
Sift the dry ingredients together.
In a large mixing bowl, cream the butter.
Mix in the mozzarella cheese.
Add the flour mixture, and mix well.
Shape into ¾ inch balls.
Place on an ungreased baking sheet.
Bake for 15 to 20 minutes, or until the balls are puffed and golden brown.
Makes one dozen.