- 2 2/3 cups sugar
- 1 cup water
- 1 1/2 tablespoons grated orange peel
- 3 cups walnuts (about 12 ounces)
- 3 cups almonds (about 12 ounces)
- 16zwieback rusks, broken coarsely, or 1 cup ground graham crackers
- 3/4 teaspoon ground cinnamon
- 12 large eggs, separated
- 1/2 teaspoon vanilla extract
- 1/2 teaspoon salt
- Preheat oven to 350°F. Butter and flour 13x9x2-inch metal baking pan. Bring 1 cup sugar, 1 cup water and 1/2 tablespoon orange peel to boil in heavy small saucepan, stirring often; boil 2 minutes. Refrigerate syrup uncovered.
- Finely grind all nuts, zwieback, cinnamon, and 1/3 cup sugar in processor. Using electric mixer, beat egg yolks, vanilla, 1/3 cup sugar, and remaining 1 tablespoon orange peel in large bowl until very thick, about 4 minutes. Using clean beaters, beat whites and salt in another large bowl to soft peaks. Gradually add 1 cup sugar; beat until stiff but not dry. Fold whites into yolk mixture, then fold in nut mixture. Transfer batter to prepared pan.
- Bake cake until tester inserted into center comes out clean, about 50 minutes. Spoon cold syrup over hot cake. Cool completely. Cover; let stand up to 1 day. Cut into squares or diamonds.