Special equipment: a large copper candy cauldron, a candy thermometer and 4 metal candy rods
Add all the ingredients, except the marshmallows and pecans, into a large copper candy cauldron and bring the mixture to a boil. Cook, stirring constantly, until the temperature of the fudge reaches 240 degrees F, 30 to 40 minutes. Pour out the fudge mixture onto a marble slab set with 4 metal candy rods arranged in a large rectangle and allow to cool for 10 to 15 minutes. When the fudge is slightly set, remove the bars and, using a long-handled paddle, cream the mixture, bringing the temperature down and adding air into the fudge to make the texture creamy and smooth, 10 to 15 minutes.
When the mixture is almost completely cool, add the marshmallows and pecans and continue to mix until the mixture becomes slightly difficult to move. Form into a log approximately 8 by 25 inches and allow to cool completely until ready to slice. Slice the fudge into 1-pound pieces, approximately 1 1/4-inches thick.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Alaskan Fudge Company, Juneau, Alaska