For the puff, melt the Water (1 cup) and Unsalted Butter (1/2 cup) together in a small saucepan over medium-high heat.
Once it's melted, add the All-Purpose Flour (1 cup) all at once and stir vigorously with a wooden spoon. Continue to stir over the heat for another 3-5 minutes. Trying to steam out some of the water content so the puff doesn't fall when it bakes.
Let the mixture cool for about 15 minutes until warm.
Preheat the oven to 400 degrees F (200 degrees C).
Take the butter/flour mixture and add in one Egg (4) at a time stirring until combined each time.
With a small cookie scoop, turn out 22 puffs on the baking sheet placing them 2 inches apart from each other. Bake for 30-35 minutes.
Let the puffs cool and cut them into sandwiches, leaving more room on the bottom. You can scoop out the extra bread or leave it.
For the filling, in a small saucepan, whisk Granulated Sugar (1 cup), All-Purpose Flour (1/3 cup), and Smith Teamaker® Matcha (1 tablespoon) together until uniform. Add Milk (1 cup) and place over medium-high heat whisking continuously. Heat until the mixture has thickened to a paste.
Take off heat and whisk in Vanilla Extract (1 teaspoon). Pour into a shallow bowl and cover with plastic wrap directly on the pudding mixture so it won't create a film. Place in the fridge and let come to room temperature.
For the filling, whip the Unsalted Butter (1 cup) until white.
Turn the mixer down to medium/low and scoop out the cooled matcha pudding one large spoon full at a time into the butter. Once the pudding has all been added, turn the beater back on high and add in the Heavy Cream (1/3 cup).
Pipe the filling into each cream puff. It won't need a lot since it's a rich matcha cream.
Dust with powdered sugar if desired and enjoy!