1Heat oven to 350°F. Grease bottom and sides of jelly roll pan, 15 1/2x10 1/2x1 inch, with shortening, or line with aluminum foil. In large bowl, mix 1/2 cup brown sugar, 2/3 cup butter, 1/2 cup corn syrup, 1 teaspoon vanilla and the egg with spoon. Stir in flour and salt. Spread in pan. Bake 18 to 20 minutes or until light golden brown.
2In 1 1/2-quart saucepan, heat 1/3 cup brown sugar and 1/3 cup corn syrup over low heat, stirring constantly, until sugar is dissolved. Stir in 1/4 cup butter and the whipping cream. Heat to boiling over medium heat; remove from heat. Stir in 1 teaspoon vanilla.
3Sprinkle cashews over crust. Pour cooked mixture over cashews; spread evenly. Bake 15 to 20 minutes or until light brown and set. Cool completely, about 1 hour. For bars, cut into 10 rows by 6 rows.