Preheat the oven to 160°C conventional heat.
Line the bottom of a 20-centimeter round cake pan with parchment paper.
Separate the eggs carefully while they are cold, then allow them to come to room temperature.
Place the egg yolks in a large mixing bowl and whisk with approximately 50 grams of the granulated sugar until lighter in color.
Add the milk and vegetable oil, whisking gently until combined.
Add the vanilla extract and lemon zest, whisk until smooth.
Sift the cake flour, cornstarch, and salt into the yolk mixture and gently combine.
Whip the egg whites, adding lemon juice or cream of tartar if using, until foamy.
Gradually add the remaining sugar while whipping until glossy and firm peaks form.
Fold the whipped egg whites into the yolk batter in three additions.
Pour the batter into the prepared cake pan and gently tap it to remove air bubbles.
Bake for approximately 45 to 55 minutes, checking for doneness.
Allow the cake to cool for about 10 minutes before removing it from the pan.
Prepare the whipped cream by whipping cold heavy cream with powdered sugar and vanilla extract until soft peaks form.
Once the cake is cool, top with whipped cream and fresh fruit if desired.
