Beat the egg yolks and sugar until very light, about 5 minutes. Slowly add
the water. Sift the flour and baking powder together. Mix with 1 cup of
nuts. Fold the flour mixture into the egg yolks. Beat the egg whites until
soft peaks form. Gently fold the beaten whites into the batter. Pour into
a greased and floured 10-inch springform pan. Bake at 375 degrees F for 30
minutes or until cake is done. Cool cake on a wire rack. When completely
cooled, split the cake into 2 layers. Fold the vanilla, confectioners
sugar, and remaining 1/2 cup of nuts into the whipped cream. Spread whipped
cream between the 2 cake layers and on top of the cake. Chill until serving
time. Garnish with fresh strawberries, if desired. * Hazelnuts are
available at most stores under the name of Filberts. They should be
blanched. To blanch, boil the nuts for 5 minutes and when they are cool
enough to handle, remove the skins. To grind, place about 1/4 cup at a
time in a blender, or chop as finely as you can with a sharp knife.