Line a 9×13-inch square pan with aluminum foil, leaving enough on the ends to allow you to lift the fudge out later. Spray with nonstick cooking spray.

Stir together sugar, butter, evaporated milk, pumpkin, corn syrup, and pumpkin pie spice in a large saucepan over medium-high heat. Stir constantly while you cook the mixture until a candy thermometer registers 234° (soft ball stage) or for about 12 minutes.

Once mixture reaches this temperature, remove it from heat.

Immediately stir in the white chocolate, marshmallow creme, nuts (if using), and vanilla. Stir until smooth.

Pour into the prepared pan. Let stand at room temp for 2 hours. Then carefully lift the fudge out by the foil “handles” and cut into squares.