Heat 1/2 cup of heavy cream and 1 tablespoon of corn syrup to a boil in a small pan.
Pour 10oz. of bittersweet chocolate into a glass bowl. Then pour boiled cream in and leave it alone for one minute.
After one minute start stirring in the middle with small circles until the mixture starts coming together. Once all the chocolate is melted put about 2 tablespoons of room temp butter in (in small chunks so it is easier to melt) and stir it until blended. Then add a couple teaspoons of vanilla extract and stir it in.
Pour your newly made ganache into a pan big enough to spread it out to about 1/2 to 3/4 inch thick, cover it with plastic wrap touching the chocolate, and let it sit until it reaches room temp. Takes about an hour.
Once it is about 72 degrees remove the plastic wrap and aggitate/fold the chocolate a little. Not to much. It is supposed to help it form more stable crystals and set properly.
Put the chocolate in a pastry bag and start the first stage of your truffles. I usually just put it in a ziplock bag and cut off a corner. It's easy and you don't have to clean the bag.
They're ugly right now, but let them set for a half hour or so before messing with them again...