Butter an 8x8 dish and set aside.

On the stove top in a heavy bottomed medium saucepan, add the sugar and evaporated milk. Stirring continuously, cook until the temperature reads 240 degrees F (soft ball stage). Remove from heat and add the peanut butter, marshmallow fluff and vanilla. Stir until smooth.

Pour the fudge into the prepared dish, and let cool before cutting (about 1 to 2 hours).

Enjoy!