Combine chocolate, cream, and salt in the top of a double boiler or heat-proof bowl over simmering water. Cook, stirring, until the mixture is smooth and chocolate is melted.

Remove the pan or bowl from the outer pan and let the mixture stand until it comes down to room temperature. Add the bourbon, vanilla, and chopped nuts. Gently stir to combine.

Cover and refrigerate the mixture for at least 6 hours. Working quickly, shape small scoops of the chocolate mixture into small balls. Place them on a baking sheet and cover them loosely. Refrigerate the truffles for several hours. Roll in finely chopped pecans, unsweetened cocoa, or granulated sugar.