Lightly grease a 9 x 13-inch baking pan and set aside.

Combine the sugar, corn syrup, butter, and evaporated milk in a large saucepan. Cook over medium heat, stirring occasionally, until the mixture reaches 242.5 degrees F on a candy thermometer, between the soft- and hard-ball stages.

Remove from the heat and stir in the remaining ingredients. Beat the mixture with a large wooden spoon until it gets very stiff. Pour into the prepared pan and let harden.

To serve, cut into pieces about 1 1/2 inches square.

Store in an airtight container, with layers of fudge separated by waxed paper.