Step 1Lightly grease 8-inch-square baking pan with 2 tablespoons oil. Sprinkle with ground walnuts and set aside.
Step 2Mix egg yolks and 1 1/4 cups sugar on high speed until light and fluffy. Add matzo cake meal and salt alternately with 3/4 cup oil, lemon juice and zest, and mix well.
Step 3Beat egg whites until stiff but not dry. Using rubber spatula, fold 1/4 beaten egg whites into egg yolk mixture until well blended. Fold in remaining beaten egg whites.
Step 4Pour half batter into baking pan. Sprinkle 1 cup Charoset over batter. Combine 2 tablespoons sugar and cinnamon and sprinkle half over top. Drop large dollops of batter over Charoset and spread evenly. Sprinkle with 1 cup Charoset and remaining cinnamon-sugar. Batter will fill pan completely.
Step 5Bake at 350 degrees until toothpick inserted into center comes out clean and cake is golden brown, 1 hour.