Combine oil, chococlate, and sugar. Add eggs one at a time, beating well after each addition. Add vanilla. Stir flour, baking powder and salt into oil mixture. Add nuts. Chill for several hours or overnight. Roll dough into balls by teaspoonfuls. Roll into confectioners' sugar. Place 5 cm apart on greased baking sheet. Bake at 180ºC or 10 to dozen minutes. Do not overbake. Yields 6 to 7 dozen cookies.