Preheat oven to 340F (170C). Grease the bottom and sides of a 8-inch (20cm) round cake pan. Set aside.
In a large bowl beat the egg whites with a pinch of salt until foamy, then gradually add sugar, until stiff peak form.
Add egg yolks and whisk until combined.
Sift in flour and gently fold until combined.
In a small bowl whisk milk, oil and vanilla extract. Add 1-2 tablespoons from the cake batter and mix until combined. Pour into the cake mixture, gently whisk until combined.
Pour the batter into prepared pan, tap the pan on the table to release air bubbles and bake for 30-35 minutes.
Allow to cool.
Frequently asked questions:CAN WE MAKE VANILLA SPONGE CAKE AHEAD OF TIME?Yes, you can make vanilla sponge cake ahead of time. Keep it in the refrigerator, covered, up to 3 days, then frost with your favorite frosting and serve.WHAT MAKES THIS VANILLA SPONGE CAKE SO AIRY?What makes this sponge cake (Genoise) so soft and airy is the use of separated eggs. First we whip the egg whites, then add the egg yolks, this makes the cake very airy and spongy.HOW CAN WE FROST THIS SPONGE CAKE?There is plenty option to frost or decorate this sponge cake. You can cut the cake in half, spread whipped cream in the middle, top with some fresh fruits, then top with the second layer of cake and repeat the process with the top of the cake. You also can use chocolate buttercream to frost this cake, vanilla cream cheese frosting.