Preheat the oven to 340°F (170°C).

Prepare two clean, dry bowls. Separate the egg whites and yolks of the 3 eggs.

Add milk and vegetable oil to the egg yolks, and mix well.

Sift in the cake flour and cornstarch, and mix in a zigzag pattern to avoid gluten formation.

Add a little white vinegar and sugar to the egg whites, and beat with a mixer.
(Start on low speed to break up, then high speed for about 2 minutes until large patterns form, then low speed for 1 more minute until soft peaks form.)

Fold about one-third of the meringue into the egg yolk mixture using a cutting or folding motion.
(Avoid stirring in circles to prevent deflating.)

Pour the mixture back into the remaining meringue and fold gently.
(Mix quickly to avoid deflating.)

Pour into a 6-inch mold, tap a few times to release large air bubbles, and place in the oven.

Bake on the lower-middle rack at 340°F (170°C) for 10 minutes, then at 300°F (150°C) for 20 minutes, and finally at 390°F (200°C) for 10 minutes to brown.

Remove immediately, tap twice to release heat, then invert to cool.

While cooling, prepare the fruit.
(Choose fruits with low water content.)

Once cooled, remove from the mold and slice into 4 layers, with the top layer being thinner and not used.

Add sugar to the heavy cream and beat on high speed for about 4-5 minutes until stiff peaks form.

Transfer to a piping bag (with or without a nozzle).

Pipe a ring of whipped cream around the cake's edge, spread a thin layer in the middle, then add fruit pieces. Cover with another cake layer.
(Repeat the same steps for the lower layer)

For the top layer, reserve some nice-looking fruit for decoration.