1 large egg, separated
1/2 cup skim milk
2 1/2 teaspoons grated lemon zest
2 teaspoons granulated sugar
1/2 cup all-purpose flour
1/2 teaspoon baking powder
1/2 teaspoon salt
2 teaspoons stick margarine, melted
1/2 teaspoon butter flavoring
3 egg whites
2 tablespoons lemon juice
2 teaspoons confectioners sugar
Preheat oven to 450° F. Spray an 8″ oven-proof skillet or cake pan with nonstick cooking spray.
In large bowl, beat egg yolk with milk, lemon zest and sugar. Sift flour, baking powder and salt together, and gradually whisk into yolk mixture. Add margarine and butter flavoring, and beat until smooth.
In another bowl, beat the four egg whites until stiff but not dry; fold into yolk mixture.
Pour into prepared skillet and bake 10 minutes. Reduce heat to 350° F. and bake 7-10 minutes more, or until toothpick inserted near center comes out clean.
Sprinkle with lemon juice and confectioners sugar, and serve immediately.