In a heavy-bottomed saucepan, combine the granulated sugar, butter, and evaporated milk. Bring the mixture to a full rolling boil over medium heat, stirring constantly to prevent scorching.

Continue to boil the mixture for exactly 5 minutes, making sure to stir continuously. This ensures the fudge reaches the correct consistency.

Remove the saucepan from the heat and immediately stir in the chocolate chips, marshmallow creme, and vanilla extract until everything is melted and the mixture is smooth and well combined.

Quickly pour the hot fudge mixture into a prepared 8x8 inch baking dish lined with parchment paper. Allow it to cool completely at room temperature or chill in the refrigerator until firm.

Once the fudge is firm, lift it out of the dish using the parchment paper and cut it into small squares. Store in an airtight container at room temperature.