Line a 9x13-inch baking pan with foil or parchment paper, leaving some hanging over the sides for easy removal.
Combine the granulated sugar, light brown sugar, evaporated milk, canned pumpkin, butter, and pumpkin pie spice in a medium saucepan. Bring to a full rolling boil over medium heat, stirring constantly. Boil, stirring constantly, for 10 to 12 minutes or until candy thermometer reaches 234° to 240º F.
Quickly stir in the white chocolate chips, marshmallow creme, pecans, and vanilla extract. Stir vigorously for 1 minute or until the chocolate chips are melted. Immediately pour into the prepared pan.
Let stand on wire rack for 2 hours or until completely cooled. Refrigerate tightly covered overnight. Cut into 1 inch pieces.
