Start by lining your 9x9-inch baking pan with parchment paper. This will ensure the fudge comes out easily once it’s set. Leave some overhang to lift the fudge out later.
In a medium saucepan, combine the 3 cups of granulated sugar, 1 cup of salted butter, and 1 cup of evaporated milk. Stir over medium heat until the mixture comes to a rolling boil.
Continue to boil the mixture, stirring constantly for about 5 minutes. This is crucial for achieving that perfect fudge consistency. Remove from heat when the time is up.
Once removed from heat, immediately stir in the 2 cups of chocolate chips and the jar of marshmallow fluff. Stir until both are completely melted and the mixture is smooth.
Next, fold in the 1 cup of chopped walnuts and 1 teaspoon of vanilla extract. Make sure everything is well combined.
Pour the fudge mixture into the prepared baking pan. Spread it evenly with your spatula, and let it sit at room temperature until fully set. This usually takes around 4 hours, but for best results, let it set overnight.
Once the fudge is set, lift it out of the pan using the parchment paper overhang. Cut it into squares and enjoy your homemade Original Fantasy Fudge!