Directions

1. Heavily butter a 15-in. x 10-in. x 1-in. pan; set aside. Heavily butter a large bowl; set aside. In a stand mixer, beat egg whites until stiff peaks form. In a heavy saucepan over medium heat, combine the sugar, corn syrup and water. Cook and stir until sugar is dissolved and mixture cones to a boil, about 10 minutes. (If sugar crystals are present, cover and boil for 1-2 minutes to allow steam to wash crystals down.) Cook, without stirring, until a candy thermometer reads 238 degrees F (soft ball stage), about 6-8 minutes.
2. With mixer running carefully and slowly add hot liquid in a steady stream over egg whites. Beat 10 minutes longer or until mixture holds its shape and is lukewarm. (Mixture will be beginning to lose its gloss.) Transfer to prepared bowl.
3. For almond mixture, in a large heavy saucepan over medium heat, combine sugar and corn syrup. Cook and stir until sugar is dissolved and mixture comes to a boil, about 15 minutes. (If sugar crystals are present, cover and boil for 1-2 minutes to allow steam to wash crystals down.) With a clean spoon, cook and stir over medium-high heat until a candy thermometer reads 275 degrees F (soft-crack stage), about 15 minutes longer.
4. Pour over mixture in bowl (do not scrape saucepan). With a large wooden spoon, stir until blended. Combine butter and vanilla; gradually add to almond mixture until blended. Transfer to prepared pan. Let stand at room temperature for several hours or until firm. Cut into squares. Wrap in plastic wrap or waxed paper if desired.