- Butter and flour for the cake pan
- 4 large eggs, separated
- 1 cup plus 1 tablespoon granulated sugar
- 2 teaspoons grated lemon zest
- 12 ounces walnuts, finely ground (pulse a few times in a food processor)
- Confectioners sugar, cocoa powder, and fresh berries for garnishing
- Preheat the oven to 375°F. Lightly butter and flour an 8-inch round cake pan. Using an electric mixer fitted with the paddle attachment, or by hand with a wooden spoon, beat the egg yolks and granulated sugar together until light and fluffy, about 4 minutes. Stir in the lemon zest.
- In another bowl, using the whisk attachment, beat the egg whites until they hold stiff peaks. Fold one-quarter of the whites into the egg-yolk mixture to lighten it. Add the ground walnuts, stirring until thoroughly blended. Carefully fold in the remaining egg whites to maintain a light texture.
- Pour the batter into the prepared pan and bake for 55 to 60 minutes or until firm and golden brown. Cool on a rack before removing the cake from the pan.
- Cut into wedges and serve garnished with confectioners’ sugar, cocoa powder, and fresh berries.