Follow these easy steps to create your amazing sponge cake:

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C). Grease and flour an 8-inch round cake pan.

2. Separate Eggs: Separate the egg whites from the yolks into two different bowls.

3. Whisk Egg Yolks: In the bowl with the yolks, add the granulated sugar. Whisk them together until the mixture is pale and fluffy.

4. Add Wet Ingredients: To the egg yolk mixture, add the milk, vegetable oil, and vanilla extract. Mix until well combined.

5. Sift Dry Ingredients: In a separate bowl, sift together the all-purpose flour, baking powder, and salt.

6. Combine Mixtures: Gradually add the dry ingredients to the wet ingredients, mixing gently until the batter is smooth.

7. Beat Egg Whites: In the bowl with the egg whites, use an electric mixer to beat them until stiff peaks form.

8. Fold Egg Whites: Gently fold the beaten egg whites into the cake batter. This step is crucial for achieving a light and airy sponge cake.

9. Pour Batter: Pour the batter into the prepared cake pan and smooth the top.

10. Bake: Place the cake in the preheated oven and bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.

11. Cool the Cake: Remove the cake from the oven and allow it to cool in the pan for about 15 minutes. Then, gently transfer it to a wire rack to cool completely.