In a large mixing bowl, cream butter and sugar until light; add vanilla then beat in eggs and melted chocolate.
Stir in dry ingredients alternately with milk. Stir in chopped pecans.
Shape dough into 1-inch balls (stir if necessary to make the dough firmer). Roll balls in confectioners' sugar and place on lightly greased baking sheets about 2 inches apart. Bake at 350° for 14 to 16 minutes, or until cookies are firm in the center. Remove from baking sheets and cool on racks. Sprinkle warm with additional powdered sugar from shaker or sifter, if desired.
Makes about 4 dozen cookies.