Flourless Walnut Cake

Directions

1. 1
   Preheat the oven to 375F.
2. 2
   Lightly butter and flour an 8-inch round cake pan.
3. 3
   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.
4. 4
   Stir in the lemon zest.
5. 5
   In another bowl, using the whisk attachment, beat the egg whites until they hold stiff peaks.
6. 6
   Fold one-quarter of the whites into the egg-yolk mixture to lighten it.
7. 7
   Add the ground walnuts, stirring until thoroughly blended.
8. 8
   Carefully fold in the remaining egg whites to maintain a light texture.
9. 9
   Pour the batter into the prepared pan and bake for 55 to 60 minutes or until firm and golden brown.
10. 10
    Cool on a rack before removing the cake from the pan.
11. 11
    Cut into wedges and serve garnished with confectioners sugar, cocoa powder, and fresh berries.