- ½ cup matzo cake meal
- ¼ cup potato starch
- 6 large eggs, separated
- ¾ cup sugar
- 1 teaspoon strained fresh lemon juice
- 1 teaspoon finely grated lemon zest
- Pinch of salt
- 2 Golden Delicious apples (10 to 11 ounces), peeled, cored, and cut into 1/8-inch slices
- 2 teaspoons ground cinnamon mixed with 1 tablespoon sugar
- Preheat oven to 325°F. Have ready a 9-inch springform pan; do not grease it.
- Sift cake meal with potato starch into a bowl. Beat egg yolks in a large bowl with an electric mixer. Beat in ½ cup sugar. Whip at high speed about 5 minutes or until mixture is pale and very thick. Stir in lemon juice and zest.
- In another large clean bowl, beat egg whites and salt with a mixer until soft peaks form. Gradually beat in remaining ¼ cup sugar. Beat at high speed until whites are stiff and shiny but not dry.
- Fold cake meal mixture into yolks. Lightly fold in whites in 3 batches, just until batter is blended.
- Lightly spoon about one third of the batter in prepared pan. Gently cover with half the apples. Sprinkle them with 2½ teaspoons cinnamon mixture. Top with half the remaining batter, then with the remaining apples, and sprinkle them with the remaining cinnamon mixture. Spoon remaining batter over apples and spread gently.
- Bake about 1 hour or until top is firm and a cake tester inserted in cake’s center comes out clean. Cool in pan on a rack 10 minutes. Run a metal spatula carefully around cake. Remove sides of pan. Cool completely. (Cake can be kept, covered, 2 days in refrigerator.)