Preheat the oven to 350 degrees F (175 degrees C).
In a medium bowl, mix together the butter and vanilla until well blended. Sift together the confectioners' sugar, rice flour, cornstarch, tapioca starch and gelatin. Stir into the butter mixture until all of the dry ingredients have been absorbed.
Mix in the ground hazelnuts and chopped hazelnuts. Form teaspoonfuls of dough into balls, and shape into crescents.
Place cookies at least 2 inches apart onto ungreased cookie sheets.
Bake for 8 to 10 minutes in the preheated oven, until golden brown. For crispier cookies, reduce heat to 325 degrees F (165 degrees C), and bake slightly longer. When cookies have cooled completely, dust with additional confectioners' sugar.
