In the bowl of a stand mixer, with the whisk attachment, beat eggs and sugar together, for 4-5 minutes until foamy.
Add oil and vanilla extract, beat for 1 minute, until combined.
In a bowl. sift together flour, salt, baking powder and Matcha powder.
Add dry ingredients to the wet ones and beat until just combined.
Preheat oven to 325F.
Spray two 8-inch cake pans with oil spray, line with parchment paper and spray over the paper.
Divide mixture between both pans.
Bake for 25-30 minutes, until cooked through (I usually bake for 30 minutes).
Let the cake cool inside the pans for 5 minutes, then carefully remove and transfer to a cooling rack to cool completely.
In the bowl of a stand mixer with the whisk attachment, beat together mascarpone cheese, sugar, heavy cream and vanilla extract fo
In a small saucepan, combine sugar and water. Bring to a boil. Stir to make sure the sugar is dissolved.
Remove from heat. Cool completely.
In a small saucepan heat heavy cream, until it just starts to boil. Remove from heat. Add white chocolate.
Slowly start to mix the mixture with a whisk or a spatula (it may take a few minutes), until incorporated. Cool.
If it gets too hard, you may add more heavy cream to thin it.
Beat egg whites for 1 minute on medium speed. Add cream of tartar.
Slowly add sugar, beating on medium-high. Beat until stiff peaks form. (Whisk attachment should leave stiff peak and mixture should look glossy).
Add vanilla extract and beat to combine.
Fill a pastry bag (use a tip of your choice like open or closed star tip, I just cut off the tip of the bag for these cookies) with the meringue mixture.
Line baking sheets with parchment paper and pipe 1/2 inch cookies, leaving space between them.
Bake at 175 F for 1 hour and 30 minutes and then let cookies cool inside the oven.
Cut off the dome from each cake, then using a serrated knife, slice each cake in half.
Place the first layer on a cake platter. Brush with simple syrup. Spread generous amount of cream on top. Add the second layer, repeat the process. Repeat with the third layer and add the fourth one. Do not brush the fourth with simple syrup. Spread some cream on the top of the cake and the sides. Scrape with a spatula to achieve the "naked" look.
Fill a small piping bag/ zip lock bag with ganache. Ganache needs to be thin and runny. Squirt ganache on the edge to the cake, and it will drip down.
Decorate cake with meringue cookies, dust with matcha.