Described as “a marvelous company hot bread” by Marion Flexner in her 1949 cookbook Out of Kentucky Kitchens, this bread is both cake-like and light.
2 cups flour
2 eggs, separated
1⁄2 cup butter at room temperature
1⁄4 cup sugar
1⁄2 cup milk
1⁄2 yeast cake (this is the equivalent of 21⁄4 quarter teaspoons active dry yeast)
1/2 teaspoon salt
Kosher salt for the top of the bread
Cream butter and sugar. Add well-beaten yolks, salt and flour, alternating with pasteurized milk that has been heated until lukewarm, and mixed with yeast. Fold in well-beaten egg whites. Put in a greased pie pan, either treated glass or pottery, and let stand until it doubles its bulk (2 1⁄2 to 3 hours). Sprinkle the top with kosher salt. Bake 25 to 30 minutes in an oven set at 375 degrees.
When the bread is golden-brown and tests done, remove from the oven, cut into pie-shaped wedges and butter while hot.
Leftover Sally Lunn can be buttered and toasted under the flame in stove. Brown on buttered side only.