Preheat the oven to 170°C (338°F). Line the bottom of a 20 cm (8-inch) round springform pan with parchment paper and grease the sides lightly. Separate eggs into yolks and whites in two large bowls. Bring milk to warm (not hot) and set aside.

Whisk yolk mixture

Whisk the 5 egg yolks lightly with 30 g of the granulated sugar until combined. Add the vegetable oil, warm milk and vanilla extract and whisk until smooth. Sift the cake flour and matcha powder together into the yolk mixture along with a pinch of salt. Fold gently with a spatula until just combined and no dry streaks remain. Do not overmix.

Make meringue

In the bowl with egg whites, start beating on medium speed. When foamy, add the remaining 70 g granulated sugar gradually in thirds while continuing to beat. Add the sugar slowly until glossy, stiff peaks form. The meringue should hold a peak and be smooth.

Combine batter

Fold one-third of the meringue into the yolk-matcha batter to loosen it using a rubber spatula. Then gently fold in the remaining meringue in two additions, using an under-and-over folding motion to preserve as much volume as possible until a homogenous, airy batter remains.

Bake

Pour the batter into the prepared pan, smooth the top lightly. Tap the pan gently on the counter to release large air bubbles. Bake at 170°C (338°F) for 25–30 minutes, or until the cake is lightly springy and a toothpick inserted in the center comes out clean. If the top browns too quickly, lower the oven to 160°C and tent with foil for the last 5–10 minutes.

Cool

Remove from oven and run a knife around the edge of the pan to prevent sticking. Invert the pan onto a wire rack and remove the bottom parchment so the cake cools completely right-side-up to avoid collapse (about 1 hour). For best texture, cool completely before slicing.

Sugar Syrup (optional)

While the cake bakes, combine 30 ml water and 15 g granulated sugar in a small saucepan. Heat just until the sugar dissolves and the mixture comes to a simmer. Remove from heat and cool. Brush lightly over the cooled cake layers if you want added moisture and shine.

Whipped Cream & Filling

Prepare cream base

If using cream cheese for body, beat the 60 g room-temperature cream cheese with 10 g of the powdered sugar until smooth and lump-free. This step is optional but helps the filling hold shape.

Whip cream

Chill a mixing bowl and whisk attachment briefly. Pour the 400 ml chilled heavy cream into the bowl and whisk at medium-high speed until it starts to thicken. Add the remaining powdered sugar (30 g) and the 3 g sifted matcha powder, then continue to whisk to soft–medium peaks. If you prepared cream cheese, fold the whipped cream into the cream cheese gently until uniform.

Assemble layers

Using a long serrated knife, slice the cooled sponge horizontally into two even layers. Place the bottom layer on your serving plate. Optionally brush the layer lightly with sugar syrup. Spread about two-thirds of the matcha whipped cream over the bottom layer in an even layer (reserve the rest for the top and piping). Place the second sponge layer on top and press gently. Cover the top and sides with the remaining whipped cream using an offset spatula. Smooth or texture as desired.

Chill

Chill the assembled cake in the refrigerator for at least 1 hour (preferably 2–3 hours) to let the cream set and flavors meld.

Garnish

Before serving, dust the top lightly with 1 tsp sifted matcha powder using a fine sieve. Sprinkle toasted sliced almonds or arrange mochi pieces around the edges if using. Slice with a hot, dry knife for clean cuts.