Prepare your ingredients and equipment by measuring out all ingredients and lining a 9x13-inch baking pan with parchment paper.
In a heavy-bottomed saucepan, combine sugar, butter, and evaporated milk. Cook over medium heat, stirring constantly until the mixture comes to a boil.
Attach a candy thermometer to the saucepan and continue cooking, stirring constantly, until the mixture reaches 234°F (112°C).
Remove from heat and quickly stir in chocolate chips until melted and smooth. Then add marshmallow creme and vanilla extract, mixing until well combined.
Pour the fudge mixture into the prepared pan, smoothing the top with a spatula. Allow to cool at room temperature for about 4 hours or until set.
Once set, lift the fudge out of the pan using the parchment paper and cut into squares.
Notes
Store in an airtight container at room temperature for up to 2-3 weeks. Can be frozen for longer storage.