Melt the unsweetened baking chocolate in double boiler or microwave. Pour melted chocolate into a mixer and add sugar, vanilla, and oil.  Mix well. Add eggs, one at a time, blending well after each one.
 
Stir together flour and baking powder and add to chocolate mixture. Mix well. If the dough is on the dry side, add a few drops of water until you achieve pliable dough.
 
Let it firm up in refrigerator for a few hours.   This is an important step, do not skip.
 
Roll dough into small ball, and then roll in powdered sugar until coated. Put them on a greased cookie sheet and bake for 12 minutes at 350 F.