Step 1

Line a 9x13 inch pan with parchment paper.

Step 2

In a large, heavy saucepan, over medium heat, mix sugar, butter, and evaporated milk.

Step 3

Bring mixture to a boil, leave on heat until the mixture registers 234°F on a candy thermometer (about 5 minutes), stirring constantly.

Step 4

Remove from heat and stir in peanut butter until thoroughly combined.

Step 5

Beat in marshmallow fluff and vanilla extract.

Step 6

Transfer fudge to the prepared pan and let cool for about 2 hours before cutting.