Heat oven to 190°C (180°C for dark or nonstick pans). Line bottoms only of two 13x23cm pans with foil or waxed paper; spray with baking spray with flour.
In large bowl, beat eggs with electric mixer on high speed about 5 minutes or until thick and lemon colored. Add cake mix, water and oil; beat on low speed 30 seconds, then on medium speed 2 minutes, scraping bowl occasionally. Place half the batter in each pan. Spread batter slightly higher in corners than at the center.
Bake 13 to 17 minutes or until cake springs back when lightly touched in center. Run knife around edges of pans to loosen cakes if necessary. Turn each cake upside down onto clean kitchen towel each sprinkled with 1 tablespoon powdered sugar; carefully remove foil. Cool completely, about 45 minutes.
In medium bowl, beat 180ml of the whipping cream on high speed until stiff peaks form; set aside. In another medium bowl, beat cream cheese and 3 tablespoons powdered sugar on medium speed until smooth; set aside.
In small microwavable bowl, microwave white chocolate baking chips and 2 tablespoons whipping cream on High 30 seconds; stir. Microwave 15 to 30 seconds longer; stir until chips are melted. Stir melted chips into cream cheese mixture. Add whipped cream and toffee candy to mixture; stir until well blended. Cover; refrigerate at least 1 hour.
Trim edges of cakes to make even. Cut each cake in half lengthwise. If necessary, trim top of layers to make flat surface. Place 1 cake piece on serving platter; spread with one-third of the filling. Repeat layers twice. Top with remaining cake piece. Gently press in sides to straighten; if necessary, trim sides until even. Cover; refrigerate 30 minutes.
In medium microwavable bowl, beat butter on medium speed until smooth. On low speed, beat in remaining glaze ingredients until well blended. Reserve some of the glaze for garnish; cover and let stand at room temperature about 30 minutes or until thick enough to pipe. Meanwhile, microwave remaining glaze on High about 10 seconds or until slightly warm and spreading consistency. Spread over top of torte, letting some drip down sides. Refrigerate torte about 30 minutes or until glaze is set.
Spoon reserved glaze into decorating bag fitted with small star tip. Pipe decorative border around top edges of torte. Refrigerate at least 2 hours. (Torte can be made 2 days ahead; wrap sides tightly with plastic wrap and refrigerate.) Let cake stand at room temperature 20 minutes before serving. Store covered in refrigerator.