Walnut Torte Cake

Preheat oven to 345° F/ 170° C. Grease a 9 inch springform cake tin and line with parchment paper. In a food processor, grind the walnuts until they are the size of breadcrumbs.

Using an electric mixer, cream the butter and sugar for 3 to 4 minutes. Add the pinch of salt, then the egg yolks one at a time, beating well after each addition. Add the ground walnuts, stirring in with a rubber spatula until combined.

In a separate bowl, whisk the egg whites until you have stiff peaks. Fold one quarter of the beaten egg white into the walnut mixture to loosen it, then gently fold in the remaining egg white, folding as lightly as possible until incorporated.