In a small saucepan, melt the chocolate, stirring occasionally until melted. Remove from heat and allow to cool.
In a large mixing bowl, mix together the sugar, oil, vanilla extract, and chocolate. Add eggs one at a time, and mix well with the other ingredients. Add the flour, baking powder, and salt, and stir until all are well mixed.
Cover the bowl with a lid or plastic wrap and refrigerate for at least 3 hours.
Heat oven to 350 degrees F. Grease a cookie sheet and set aside.
Remove dough from refrigerator and scoop out a teaspoon-sized amount. Drop into a bowl of powdered sugar and roll to coat. Shape the dough into a ball. Place on the cookie sheet, spacing balls about 2 inches apart.
Bake for 10 to 12 minutes or until they don't leave an indentation when touched. Remove from cookie sheet immediately and transfer to wire rack to cool.