CAKE: Grease2 nine-inch round cake pans;line bases with wax or parchment paper.Set aside.Spread whole hazelnuts on a cookie sheet;bake in 350F oven for 8 min..Transfer to teatowel;fold over and rub off skins.Finely chop nuts in processor or grinder. In large bowl of electric mixer,beat eggs for 12 minutes. Add flour, baking powder and nuts;mix well.Pour into pans, bake in 350F oven25 min.,or until tester comes out clean.Cool 5 min..Cut around edge of pans,turn out and remove paper.With dental floss.cut cakes in half to make 4 layers.

FILLING:Cream butter with sugar;beat in coffee,cocoa and vanilla. Place 1 cake layer on serving plate;spread with 1/3 filling. Repeat with remaining layers.

TOPPING:Warm chocolate in microwave at 50% power for 32 sec.. or until slightly soft.With a veg. peeler,peel off curls. Reserve. Whip cream in bowl with liqueur and sugar. Spread over top and sides of cake. Sprinkle top with ground nuts. Arrange choc. curls on top of cake.( Cake may be prepared ahead,covered and refrigerated for up to a day.