Start by preparing the matcha cake sheet. In a large heat safe bowl, whisk the eggs to break up the yolks. Next, add the sugar, salt, and honey and whisk together to fully incorporate.

Place the bowl over a pot of boiling water and continuously whisk until the mixture heats to 107F/42C. Once it reaches the correct temperature, remove the bowl and set aside.

In a smaller bowl, combine the heavy cream and oil, then place the bowl into the hot water from earlier and allow it to heat to 122F/50C.

Back to the egg mixture, use a hand mixer and beat on high for 6-8 minutes until lighter in color and doubled in size. Then turn the hand mixer on low for 2-3 minutes to stabilize the bubble structure.

Sift in the flour and matcha powder and carefully fold in until almost fully incorporated. Then carefully pour the cream and oil mixture over the batter and gently fold it in.

Pour the batter into a parchment lined cake pan from a height of about 10 inches/25cm. Use a skewer and swirl around the batter starting from inside going out or vice versa to disrupt any large bubbles. Drop it onto the counter once then bake at 320F/160C for 30 minutes.

Once finished baking, remove from the pan and allow to cool completely on a rack.

While the cake cools, prepare the matcha syrup and the mascarpone cream. For the syrup, simply combine the hot water, sugar, and matcha powder until the powders are fully dissolved.

Next, add the egg yolks, sugar, and vanilla to a heat safe bowl and whisk it together over a bain marie. Heat the mixture up until it reaches 158F/70C. Remove from heat, and use a hand mixer to beat until light and fluffy. Set aside.

Prepare the room temperature mascarpone cheese in a separate and use a spatula to spread it around to soften it. Add the egg yolk mixture and fold until fully incorporated.

In a separate bowl, whip the heavy cream to soft peaks and add to the mascarpone mixture. Whisk together to combine. The mixture should be a pretty soft and loose consistency at this point. Prepare the cream by scooping into piping bags.

Finally, cut the cake into three 1cm layers. Now we can begin assembling the matcha tiramisu cake. Prepare a cake ring with a ring of acetate and lay down the first cake layer.

Drizzle or spoon over the matcha syrup to soak the first layer. Be careful not to put too much so it doesn’t leak. Pipe the first layer of mascarpone cream about the same thickness as the cake sheet. Repeat this with the remaining layers of cake.

Once you’ve finished piping the last layer of mascarpone cream, use an offset spatula or cake scraper to smoothen out the top.

Use a fine sieve to dust a layer of matcha powder on top then refrigerate to set. You can stop here if you’d like, but if you’d like to make the swiss meringue buttercream, then continue ahead!

In a large heat safe bowl, combine the egg whites and granulated sugar. Then heat it over a bain marie until it reaches 158F/70C, whisking constantly. Once it reaches temp, remove from heat and use a mixer to beat until stiff peaks.

Add the softened butter bit by bit while continuing to beat. The meringue may break part way through but keep going, and it will eventually come together.

You should now have a strong buttercream ready for coloring and decorating as needed!

Take the matcha tiramisu cake out of the fridge and let it come to room temp a little before adding decorations and serving. And the matcha tiramisu cake is finished! 完成です！