Line a 13x9x2-inch baking pan with foil, extending foil over edges of pan. Butter foil; set pan aside.

In a 3-quart heavy saucepan combine sugar, butter, evaporated milk, and pumpkin. Cook and stir over medium-high heat until mixture boils. Clip a candy thermometer to side of pan. Reduce heat to medium-low; continue boiling at a moderate, steady rate, stirring frequently, until thermometer registers 234 degrees F, soft-ball stage (20 to 25 minutes). (Adjust heat as necessary to maintain a steady boil.)

Remove saucepan from heat; remove thermometer from saucepan. Stir in cinnamon-flavored pieces until melted. Stir in marshmallow creme and walnuts.

Immediately spread fudge evenly in prepared pan. Score into squares while warm. Let fudge cool to room temperature. When fudge is firm, use foil to lift it out of pan. Cut into squares. Cover tightly and chill for up to 1 week. Do not freeze. Makes about 96 pieces.