Mix together the vegetable oil, melted chocolate, and granulated sugar. Add egg one at a time until blended well. Add vanilla extract.
In a separate bowl, mix together flour, baking powder, and salt. Slowly add to chocolate mixture until thoroughly mixed, and chill overnight (or for at least 2 hours).
Preheat oven to 350 degrees. Form dough into teaspoon size balls and roll in confectioners’ sugar. Place balls on a greased cookie sheet, about 2” apart, and bake for 10-12 minutes.