Hazelnut cake with chocolate and raspberries

1. For cake: preheat oven to 350°F.
2. Line 10x15-inch baking sheet with ¾ inch high sides with parchment.
3. Butteri parchment.
4. Process hazelnuts, 2/3 cup sugar and flour in processor until nuts are finely ground.
5. Using electric mixer, beat egg whites and salt in large bowl until soft peaks form.
6. Gradually add remaining 2/3 cup sugar, beating until stiff peaks form.
7. Gently fold nuts into whites in 2 additions.
8. Foldi in butter.
9. Spread mixture evenly in prepared pan. Bakei cake until golden and slightly firm in center, about 16 minutes.
10. Cool. (can be prepared 1 day ahead.
11. Cover and let stand at room temperature).
12. For chocolate ganache: bring cream to boil in heavy large saucepan.
13. Remove from heat.
14. Add chocolate and whisk until chocolate melts and mixture is smooth.
15. Transfer to large bowl.
16. Chill until mixture is cold and thick, stirring occasionally, about 45 minutes.
17. Using electric mixer, beat chocolate mixture until firm peaks form.
18. Turn out cake onto work surface; peel off parchment.
19. Cut cake lengthwise into 2 equal rectangles.
20. Place 1 layer on platter.
21. Spread cake with 1/3 of chocolate ganache.
22. Arrange 1 basketful raspberries over ganache, spacing berries evenly.
23. Top raspberries with 1/3 of chocolate ganache.
24. Place second cake layer atop cream; press gently to compact.
25. Spread top and sides of cake decoratively with remaining chocolate ganache.
26. Refrigerate until firm, about 2 hours.
27. (can be made 1 day ahead.
28. Cover; keep chilled).
29. Sifti cocoa powder over cake.
30. Cut cake into squares.
31. Place squares on plates.
32. Spoon coulis around cake.
33. Top coulis with whipped cream, if desired.
34. Garnishi with berries and mint.