Cream the softened butter and 1 c of the sugar together until light and fluffy. Add eggs and the lemon peel; blend thoroughly. Sift the flour, salt, baking soda and baking powder together. Add dry ingredients alternately with the yogurt. Fold in the ground nuts. Turn into a well-greased 9 inch tube pan. Bake at 350 degrees for 1 hour or until a toothpick inserted in the top comes out clean. Combine the 1/2 c sugar and lemon juice in a saucepan. Heat until sugar has dissolved and pour over the cake while still warm. Allow cake to cool in the pan. From "The Portable Feast" by Diane D. MacMillan, 101 Productions.