1 cup  butter
1 1/3 cup sugar
2 lemons, zested
3 whole eggs
3 egg yolks
1 tsp. vanilla
1/2 tsp. salt
1 1/2 cups cake flour

Cream butter and sugar until fluffy. Add the zest, eggs and vanilla and beat until well combined. Gently fold in salt and flour. Pour batter into a greased 8 cup loaf pan and bake 320 degrees for 70 minutes (until a toothpick comes out clean). Let the cake rest for 5 to 10 minutes before turning out on a rack to cool.