1. Whip the heavy whipping cream with granulated sugar, matcha powder, and vanilla extract until stiff peaks form.
2. Gently fold the mascarpone cheese into the whipped cream mixture, combining it until smooth. Optionally, add white chocolate or extra matcha for flavor variation.
3. Dissolve matcha powder in hot water to create a matcha syrup. Quickly dip each ladyfinger in the syrup, ensuring they are evenly coated without oversoaking.
4. Lay a base layer of matcha-soaked ladyfingers in a serving dish.
5. Spread a layer of the mascarpone cream mixture over the ladyfingers.
6. Repeat the layering process, alternating between ladyfingers and cream, until 2-3 layers are achieved, depending on the dish size.
7. Cover the assembled tiramisu and refrigerate for at least 4 hours, or preferably overnight, to allow it to set and the flavors to meld.
8. Before serving, dust the top of the tiramisu with more matcha powder for added flavor and a visually appealing finish.
9. Slice and serve chilled, enjoying the creamy texture and unique matcha flavor.