In a microwave safe bowl, melt the Ghirardelli wafers for 2 minutes at half power. Stir. Heat in 1 minute increments at half power as many times as necessary to completely melt the chocolate, stirring in between each interval. Working quickly, put each ball into the melted chocolate, covering it completely. Lift it out with a fork tapping off the excess chocolate on the side of the bowl. Place it on a sheet of parchment. If using the gold leaf, put a dab on each ball before the chocolate sets. Once you’ve dipped all your truffles, dust each with the black cocoa and a bit of cayenne pepper.