Mix butter, pumpkin, and pumpkin pie spice in a small nonstick pan and heat over medium heat for 8 to 10 minutes or until mixture is reduced to 1/2 cup. Cool to room temperature.
Mix cooked pumpkin, brown sugar, flour, and salt in medium bowl until well combined. Chill dough for 30 minutes in the refrigerator. Shape chilled dough into 15 1-inch balls. Place on waxed paper on a cookie sheet and chill in the refrigerator while preparing chocolate.
Melt white chocolate chips in a shallow bowl on High 1 minute, stirring after 30 seconds; stir until chips are melted and mixture is smooth. Mix orange gel food coloring with the melted chocolate until smooth. Using 2 forks, dip pumpkin balls into melted chocolate and cover evenly. Place on waxed paper and top each truffle with a pecan piece “stump”. Serve after chocolate sets, about 5 minutes. Makes 15 truffles.