

Gently add the whites to the batter, folding them in with a wooden spoon or a rubber spatula and barely mixing everything together. In a large bowl, beat the egg whites to stiff peaks.Scrape down the sides of the bowl and the beaters and do the final mixing by hand. Do not overmix or the cake will be tough. Mix in half the egg yolks, followed by another cup of flour, then the remaining yolks and finally the rest of the flour. Add 1 cup of the flour mixture to the butter mixture and mix well. Add sour cream, vanilla and lemon flavoring and mix well. Slowly add confectioners' sugar and beat for several minutes, until the mixture is satiny. In the large bowl of an electric mixer, cream butter on medium speed until light and fluffy.Generously spray a heavy 10-inch Bundt or straight-sided angel food cake pan with baking spray. The cake, which is a perfect base for peaches and whipped cream or another fruit topping, gets better after a couple of days and will be good for a week if you keep it well wrapped. Charles found the recipe and deciphered it, and included it in her cookbook "A Real Southern Cook: In Her Savannah Kitchen." You can use lemon juice and zest instead of lemon flavoring, which the original recipe called for, or increase the vanilla by a teaspoon if you are leaving out the lemon altogether. The patient, Mary Martin, mailed it to her long after she left the nursing home, but because of a stroke, her handwriting was shaky.

It came from Dora Charles's aunt Laura Daniels, who got it from a nursing-home patient she was working with in the 1970s. This one produces a higher, lighter cake than many recipes. The South has about as many poundcake recipes as there are grandmothers.
