You will need chocolate, either white or dark, a pallet knife, a double edge comb scraper and a metal, broad spatula. The spatula looks like a 6-inch putty knife. I've used my metal bench scraper before and it worked pretty well.
Prepare your counter by thoroughly cleaning and drying. If you have access to a huge sheet of marble, even better. I used my marble coffee table more than once.
Melt and temper your chocolate.
Spread a narrow band of tempered dark chocolate onto the clean surface. Using a palette knife spread it thinly to 5 1/2" wide. Now using the comb, create long straight lines through the length of the chocolate band. Allow the chocolate to firm slightly, then apply a second layer of chocolate on top of the chocolate. (You could make the bottom layer a dark chocolate and the top layer a white chocolate). Spread thinly and evenly with a palette knife. Allow to firm slightly. Use the broad scraper at 1" increments to roll-up the chocolate into quills.