2. Butter a 10-inch springform pan, then line it with wax paper. Butter the paper.
3. In a food processor, combine the almonds and sugar. Process until the almonds are finely ground. Set aside.
4. Separate 4 of the eggs, placing the yolks in a large bowl and reserving the whites. Add the remaining eggs, along with the salt, vanilla, and lemon peel to the bowl with the yolks and beat to blend well. Gradually beat in the almond mixture. The mixture will become very thick.
5. In a large bowl of an electric mixer, beat the reserved egg whites until they are stiff but not dry. Gently fold them into the batter, a third at a time.
6. Transfer the batter to the prepared pan and bake for 45 minutes, or until a wooden pick inserted near the center of the cake comes out clean.
7. Cool the cake in the pan on a wire rack. Remove the sides of the pan and sprinkle the cake with powdered sugar and serve with Chocolate Coffee Sauce.
Note: Incidentally, this is a great cake to serve for Passover.