Heat oven to 180°C. Grease 20cm round cake pan. In large bowl, beat cake mix, water, oil and egg whites with electric mixer on low speed 30 seconds, then on medium speed 2 minutes, scraping bowl occasionally. Pour batter into pan.
Bake for 35 to 40 minutes or until center is set. Place on wire rack. Cool 40 minutes.
Carefully run knife around edge of pan; invert cake onto wire rack. Cool an additional 20 minutes.
Meanwhile, in small saucepan make the glaze by combining whipping cream, honey and vanilla. Bring to a boil over medium heat, stirring occasionally. Remove from heat. Add 90 grams chocolate; stir until melted and smooth.
Place cake on serving platter. Place pieces of waxed paper under cake to catch drips. Slowly pour glaze over top and sides of cake to cover. With narrow metal spatula, smooth glaze over cake. Sprinkle hazelnuts around top edge of cake. When glaze is set, remove waxed paper. Store in refrigerator.