Line a 9x9 inch pan with aluminum foil, and set aside.
In a 3 quart saucepan, heat milk and sugar over medium heat. Bring to a boil, stirring occasionally with a wooden spoon.
Mix in pumpkin puree and cinnamon; bring back to a boil. Stir in marshmallow creme and butter. Bring to a rolling boil. Cook, stirring occasionally, for 18 minutes.
Remove from heat, and add white chocolate chips and vanilla. Stir until creamy and all chips are melted. Pour into prepared pan. Cool, remove from pan, and cut into squares. Store in a cool, dry place.