In a food processor, process the cookies until pulverized and powdery.
Add the mascarpone and process until fully blended.
Place in a bowl and refrigerate for an hour.
Using your hands, form the mixture into bite-sized balls, then place on a baking sheet lined with oven paper.
Refrigerate for an hour.
Melt the dark chocolate over a double boiler, then stir in 1 teaspoon oil.
Allow the chocolate to cool to room temperature.
Once the chocolate balls are chilled place them, one (or two) a time, on a two-tined barbecue fork.
Using a spoon drizzle melted dark chocolate evenly over each ball, then place each one back on the paper-lined baking sheet.
Chill the balls again while you prepare the white chocolate.
Melt the white chocolate over a double boiler, then stir in the remaining ½ teaspoon oil.
Allow the chocolate to cool to room temperature.
Place the white chocolate in an icing bag, with a tiny (almost pin point opening.
Remove the chocolate balls from the fridge and drizzle the white chocolate over them.
I find you'll achieve the best effect if you drizzle back and forth over all the balls at once, from a height of about 25 centimeters (10 inches).
Store the chocolate truffle balls in an airtight container in a cool place, or refrigerated.