Pan Di Spagna (Italian Sponge Cake )

• 5 egg yolks
• 5 egg whites
• 1 1/2 cups sugar
• 1 1/4 cups pastry flour, sifted
• 1 teaspoon vanilla
• 1/2 teaspoon grated fresh lemon rind (optional)

1. Place egg yolks and sugar in a mixing bowl and beat until lemon colored.
2. Add vanilla and lemon rind (if using it).
3. Beat egg whites until stiff but not dry and then fold into the egg yolk mixture.
4. Sift the flour in a separate bowl and slowly incorporate it into the egg mixture with a mixing spoon.
5. Butter and flour a 18inch square (or a 9 x 13 x 3, or a 11 x 17 x 2inch half-sheet) cake pan**.
6. Pour cake batter into prepared pan and bake at 375u0b0F for 40 minutes, or until toothpick inserted in center comes out clean.
7. Remove cake from oven and turn out (of pan) onto a cake rack to cool.
8. When completely cool, cake may be sliced horizontally to form 2 or 3 thin layers.
9. Cake can be tightly wrapped and frozen (up to 3 weeks) for future use.
10. **Please check your oven size, to make sure pan will fit properly.

egg yolks, egg whites, sugar, pastry flour, vanilla, lemon rind

Taken from www.food.com/recipe/pan-di-spagna-italian-sponge-cake-65221 (may not work)