ZABAGLIONE
In a mixing bowl over a pot of simmering water, whisk egg yolks, sugar, and wine for 3 minutes, until it’s thick, creamy, and the mixture holds a ribbon (lift your whisk with some of the mixture on it. It should fall and hold a ribbon shape.) You can also use an immersion blender for this step.
Remove from heat and set aside to cool.
TIRAMISU
Once custard/zabaglione mixture is cooled, gently fold in mascarpone and white chocolate.
In a separate bowl using a mixer, or by hand, whip cream and vanilla to medium peaks. Fold whipped cream into zabaglione mascarpone mixture and set aside.
In a small bowl, mix boiling water with matcha and sugar. Cool until matcha is at room temperature.
Dip half the ladyfingers into matcha mixture then arrange in trifle or 9- x 13-inch casserole dish.
Pile half of zabaglione mascarpone mixture on top of dipped ladyfingers and spread so it’s evenly distributed and smooth. Dip remaining ladyfingers and arrange top of zabaglione mixture. Add remaining zabaglione and spread with a spatula.
Dust top with matcha powder and grated white chocolate. Chill for at least 4 hours or overnight before serving.
Note: Place 6 ounces white chocolate and 11/2 tablespoons butter in a microwave safe bowl and microwave on medium heat in 30 second intervals until fully melted. Pour melted chocolate over inverted baking tray and allow to cool in fridge for 30 minutes. Bring to room temperature and use a rubber spatula to scrape chocolate curls.