I chilled the chocolate in the pan overnight.
I just scooped them from the pan into the cocoa powder.
Since I used a one teaspoon scoop I got about 80 truffles. These were the perfect bite-size piece. I stored the extras in the freezer liked Dorie suggested.
My son was experimenting with some artful pictures of the truffles.
Chocolate Truffles page 396 Baking Chez Moi.