Heat oven to 375°F. Cut dough into 1/2-inch slices. In bottom of ungreased 13x9-inch pan, arrange slices. With floured fingers, press dough evenly in bottom of pan to form crust. Sprinkle with 1/2 cup of the hazelnuts; press firmly into dough. Bake 10 to 12 minutes or until dough is puffed.
Meanwhile, in medium bowl, mix sugar and flour. Stir in corn syrup, orange peel, orange juice, melted butter and egg with wire whisk until smooth. Stir in remaining 1/2 cup hazelnuts.
Carefully pour corn syrup mixture over partially baked crust. Reduce oven temperature to 350°F.
Bake 18 to 23 minutes or until edges are golden brown and filling is set. Cool 10 minutes. Sprinkle with powdered sugar. Cool completely, about 50 minutes. For bars, cut into 6 rows by 4 rows.