"Tea powder" refers to fine particles or granules made by grinding or pulverizing tea leaves. It is commonly used to make instant tea by simply dissolving it in hot water. Full definition
You can get matcha green tea powder in any specialty tea store and more recently, in most health - food stores. (letsdrinktea.com)
I've used matcha tea powder in the tart shell as well in the filling. (sugaretal.com)
When water has boiled, in a liquid measuring cup, whisk 1 tablespoon of matcha green tea powder with 3 tablespoons of boiling water until a creamy paste forms. (cococakeland.com)