Spread the pecans on a rimmed baking sheet and bake until browned and toasted, 8 to 10 minutes. Let cool completely, then chop very finely.
Put the bittersweet chocolate, semisweet chocolate, vanilla, and salt in a large bowl. Heat the heavy cream and butter in a small saucepan over medium-low heat until the cream is steaming and the butter has melted; pour over the chocolate, then let sit for 5 minutes. Whisk together until the chocolate has melted and the mixture is smooth. If there are any bits of unmelted chocolate left, microwave in 30-second increments, stirring after each, until smooth. Add the pecans and cherries and stir to combine.
Cool the mixture to room temperature and then cover with plastic wrap and refrigerate until the mixture is firm but still pliable enough to scoop and roll, about 3 hours.
Spread some sugar on a plate and line a baking sheet with parchment paper. Shape heaping teaspoons of the chocolate mixture into balls and then roll in the sugar to coat. Store in the refrigerator.
Copyright 2016 Television Food Network, G.P. All rights reserved.