Recipe from: The Story of Pure Vanilla, rewritten by R.C. Schlotterer.
Published by the Vanilla Bean Association of America, © 1955.
Cream butter, vanilla, and half of the sugar together until light and fluffy. Blend in
melted chocolate and add egg yolks. Sift together flour, baking powder and salt. Add to
creamed mixture alternately with milk. Beat egg whites stiff, and add the rest of the
sugar slowly, beating constantly until glossy. Fold into the batter. Turn batter into
two greased 9-inch round layer pans. Bake at 350° F. 30 to 35 minutes
or until cake pulls away from pan and top is springy to touch.