Prepare the Matcha: Sift the matcha powder into a small bowl. Add the hot water and whisk vigorously until a smooth, frothy paste forms. Ensure there are no lumps.
Sweeten the Mascarpone: In a separate bowl, combine the chilled mascarpone cheese with the sugar or sweetener. Mix until smooth and well combined.
Assemble the Drink: In a glass, layer the sweetened mascarpone mixture at the bottom.
Add the Matcha: Gently pour the prepared matcha mixture over the mascarpone layer, trying to keep the layers distinct.
Top with Milk: Froth the chilled milk (optional). Carefully pour the milk over the matcha layer. If using frothed milk, spoon the foam on top.
Garnish (Optional): Dust the top of the drink with cocoa powder for an authentic tiramisu touch.
Serve: Serve immediately and enjoy. For an iced version, chill all components before assembly and pour over ice.
Tips and Substitutions: For a dairy-free version, substitute the mascarpone with a vegan cream cheese alternative and use a plant-based milk. Adjust the amount of sweetener to your preference. For a richer flavor, add a dash of vanilla extract to the mascarpone mixture. If you don't have a milk frother, you can shake the milk vigorously in a jar until foamy.