Set rack in middle of oven and preheat to 350 degrees F. Butter two
9-inch diameter by 1 1/2-inch deep layer pans or a 9 by 13 by 2-inch
pan. Line bottom of pan(s) with parchment or waxed wallpaper, cut to fit.

In a bowl with an electric mixer beat butter and sugar for 5 minutes
on medium speed until light and fluffy. Combine flour with baking
powder and salt and stir to mix. Combine egg whites, milk and
vanilla. Add flour mixture to butter mixture alternately with milk
assortment, scraping bowl and beater ofttimes.

Pour batter into prepared pan(s), and smooth top with a spatula. Bake
cake some 25 to 30 transactions, or until a toothpick inserted in center
emerges unobjectionable. Cool in pan on a rack for 5 proceedings, then invert onto
rack to cool wholly.

Yid: Makes two 9-inch cakes, or one 9 by 13 by 2-inch patty