Preheat oven to 350F.
Using a hand mixer, cream the butter and sugar until light and fluffy. Add the egg yolks one at a time, incorporating each before adding the next.
In a separate bowl, combine and sift the dry ingredients. Add the lemon zest to the butter mixture, then slowly add the dry ingredients, then add the wine.
In a separate bowl, add egg whites a pinch of salt. Whip the whites until stiff peaks are formed. Gently fold the whites into the batter.
Pour the batter into a ring mold and bake for thirty minutes or until a knife comes out clean.