In a small bowl, add matcha sauce ingredients and mix well.
Use a pastry brush to coat the baumkuchen with the matcha sauce and let it soak in.
In a medium bowl, add the pudding and remove the caramel. Add the flour and matcha powder; mix until smooth. Place in the microwave and heat for 1 minute at 500 watts, then remove and stir. Place back in microwave and heat for another minute, then stir.
Pour the custard into the hole of the baumkuchen. Place in refrigerator for about 30 minutes to set. Remove and sprinkle with granulated sugar. Heat a spoon over the stove, then slowly move spoon over the sugar to caramelize. Enjoy!