Sauté pecans in 1 tablespoon butter in a large nonstick skillet over medium heat until toasted. Cool completely. Pulse pecans in a food processor until finely chopped.
Combine chocolate and 2 tablespoons butter in a glass bowl. Microwave on HIGH 1 minute; stir until smooth. Stir in pumpkin, next 5 ingredients, and 1/2 cup pecans. Chill 3 hours or until almost firm.
Combine remaining 1/2 cup pecans and crushed gingersnaps in shallow dish. Shape pumpkin mixture into 1" balls; roll in pecan mixture. Cover and chill at least 3 hours. Store in refrigerator up to 1 week.