Beat egg whites, gradually adding sugar and beating until stiff. Reduce speed, then add yolks.

Sift together dry ingredients. Add to eggs, alternating with oil and juice.

Pour into two lined 16- by 12-inch cookie sheets. Bake at 350 degrees Fahrenheit for 20 minutes.

Proceed as with light cake. Pour into one cookie sheet and bake as directed above.

Cream margarine with sugars until light and fluffy. Add yolks, mixing well. Add lemon juice and beat for five minutes.

Divide cream into three parts.

Spread one part lemon cream over one light cake. Invert dark cake over cream.

Spread second part of cream over dark cake and invert second light cake over cream.

Top with remaining cream.

Cut into four logs. Cut each log to half-inch slices.