Preheat your oven to 140°C (285°F) with both top and bottom heat. Line a baking sheet with parchment paper.

Separate your egg yolks and whites, placing them in two clean, dry bowls.

In a medium bowl, combine the corn oil and milk.

Whisk vigorously until the mixture is fully blended and appears slightly creamy (emulsified).

Sift the cake flour and the 5g of matcha powder directly into the wet ingredients.

Use a whisk to gently stir in a "Z" shape until you have a smooth paste with no dry flour; be careful not to overmix.

Add the egg yolks and whisk just until the batter is uniform and smooth.

Using an electric mixer, begin whipping the egg whites on low speed.

Once they become frothy with large bubbles, gradually add the granulated sugar in three parts, increasing the mixer speed to medium-high.

Once all the sugar is added and the whites are nearly at stiff peaks, reduce the speed to low for a final minute to create a stable, smooth meringue. It's ready when you lift the whisk and the peak stands straight up.

Add about one-third of the meringue to the matcha batter.

Use a silicone spatula to gently fold it in until mostly combined. This lightens the batter.

Pour this mixture back into the bowl with the remaining meringue.

Carefully fold the two together using a cutting-and-folding motion, just until no white streaks remain. Be gentle to keep the air in the batter.

Transfer the batter to a piping bag. Pipe small, evenly-sized rounds (about 5cm in diameter) onto the prepared baking sheet, leaving about 2cm of space between them for expansion.

Bake on the middle rack for about 25 minutes, or until the cakes spring back lightly when touched. Let them cool completely on a wire rack before assembling.

Combine heavy cream, matcha powder, and sugar in a bowl. Beat on medium speed until thick and creamy. Avoid overwhipping to prevent graininess.

Transfer to a piping bag for easy assembly.

Take one cooled cake round and pipe a layer of matcha cream onto it.

Sprinkle some oat clusters over the cream.

Pipe another small dollop of cream on top of the clusters, then gently press a second cake round on top to create a sandwich.

Finally, add a small dollop of cream on the top shell and decorate with dried fruit and oat clusters. Repeat with the remaining cakes.