Mix together the crumbs, nuts, and melted butter. Pack onto the bottom of a greased 25 cm spring form pan. Chill 30 minutes. Beat together the cheese, 1 cup of the sugar, and the salt. Add the flour and egg yolks, one at a time, beating until very smooth. Beat in the lemon juice, vanilla, almond extract and sour cream. Beat the egg whites until soft peaks form, then gradually beat in the remaining sugar until stiff but not dry; fold into the cheese mixture. Slowly pour into the prepared chilled spring form pan. Bake in a preheated 160ºC . oven 1.25 hours. Open the oven door, turn off the oven, and leave the cake to cool for 1 hour. Remove from oven and finish cooling on a cake rack, then chill at least an hour before removing the sides of the pan. Serves 10 12.