Sponge Cake

Directions

1. 1
   Sift flour, measure and add salt.
2. 2
   In a large bowl, beat egg yolks until thick and lemon colored.
3. 3
   Add sugar gradually, continuing to beat.
4. 4
   Add vinegar and flavoring; beat, then fold in flour slowly, until all absorbed.
5. 5
   With clean beater, beat egg whites in separate bowl until they hold their shape.
6. 6
   With large wooden spoon or spatula, fold egg yolk mixture into beaten whites, gently; do not beat.
7. 7
   Bake in an ungreased tube pan (10-inch) at 320° for one hour.
8. 8
   After baking, invert immediately.