Remove the double boiler once the mixture is smooth and all the ingredients are melted. Be cautious when handling the double boiler, and use oven mittens, as both pans will be hot. You can also add chopped nuts, dried fruits, or any other desired toppings at this point.
Pour the fudge mixture into the prepared baking dish and spread it out evenly using a spatula.
Let the fudge cool at room temperature for a while before transferring it to the refrigerator. Chill the fudge in the refrigerator for at least 3-4 hours or until it becomes firm.
Once the fudge has solidified, lift it out of the baking dish using the excess parchment paper or foil, and place it on a cutting board.
Cut the fudge into small squares or any desired shape using a sharp knife.