• Combine the corn syrup, sugar, salt and water in heavy-bottomed saucepan and simmer, stirring until the sugar dissolves.
• Bring to boil and boil without stirring, until a small amount dropped in very cold water forms a hardball.
• Beat the egg whites in a large mixing bowl until stiff but not dry, then little by little beat in ¼ of the corn syrup mixture and continue beating until the mixture holds its shape.
• Boil the remaining syrup until the mixture reaches the hard-crack stage, then beat little by little into the first mixture.
• Continue beating until the mixture begins to hold its shape.
• Stir in the vanilla essence and the butter or margarine and beat until very thick and creamy.
• Stir in the nuts and pour into a buttered square 200 mm pan, smoothing the top, and let stand until firm.
• Turn out of the pan and cut into 2 cm pieces.

Note

• For the best flavour, store for several days in a cool place before serving.