When the ganache has cooled to the consistency of toothpaste, scrape it into a pastry bag fitted with a 1/2-inch plain tip. Pipe 1-inch-diameter mounds spaced 1 inch apart on a parchment paper-covered baking sheet.
To pipe the mounds, hold the pastry bag at a slight angle and allow the tip to touch the parchment as you begin to pipe.
Once you have formed the mound, stop squeezing and lift the tip straight up, leaving a small tail on the top of each mound, like a hershey’s kiss.
You can also use a spoon and drop small mounds of ganache onto the baking sheet.
Let the truffles harden at room temperature for a couple of hours (or in the refrigerator for 15 minutes), until they are hard enough to roll with your hands.
Place the cocoa powder, and the chopped pecans in separate bowls.
Roll each cooled ball of ganache between the palms of your hands to form into a sphere and to soften the outside of the ball.
Immediately drop them into the “topping” bowl of your choice, and roll them around with a fork or spoon to evenly coat the ganache with either the cocoa or nuts.
Move to a parchment covered sheet tray, then to the fridge for about 15 minutes to set. Recover any extra cocoa and minced nuts for future use.