Preheat oven to 325 degrees. Tightly wrap the outside of the pan containing the prebaked crust with 3 layers of heavy-duty foil, dull side out.
Using electric mixer fitted with paddle, beat cream cheese until fluffy, scraping sides and bottom of bowl.
Mix green tea powder into sugar. Add to cream cheese and continue beating.
Add eggs and egg yolks, one at a time, beating on low speed after each addition until incorporated and scraping sides and bottom of bowl. Beat in mascarpone, one tablespoon at a time.
Pour batter into prepared crust. Place the pan into a larger roasting pan and carefully add enough hot water to roasting pan to reach halfway up the outside of the springform pan.
Bake cake until set, about 1 hour. (Center should move very slightly when pan is gently shaken.) Remove cake from roasting pan. Cool completely at room temperature. Then refrigerate uncovered overnight to set before serving.
Notes
Nutrition facts not calculated with crust and toppings, as these ingredients will vary based on individual preference.