3 eggs, separated
1/4 cup granulated sugar
1/8 teaspoon salt
1/4 cup all-purpose flour
1/3 cup fresh, strained lemon juice
Zest of 1 lemon, finely chopped
1 1/2 cups buttermilk
1/4 cup granulated sugar

Grease an 8-inch square pan. Preheat oven to 350 degrees F.

Whip egg whites with the 1/4 cup sugar to soft peaks.

In a separate bowl, combine remaining wet ingredients.

Combine remaining dry ingredients in a separate bowl. Whisk the wet ingredients into dry ingredients. Carefully fold in egg whites. Pour into prepared pan. Place in a larger pan or dish and fill to halfway up sides with boiling water. Bake for 30 to 35 minutes. Serve warm or cold.