Preheat oven to 450F.
Roll out dough to fit a 9-in. pie plate. Transfer crust to the pie plate and flute the edges. Prick the pie dough with a fork, and then line with aluminum foil, fill with pie weights and bake for 8 minutes. Remove foil and weights; bake 5-7 minutes longer or until light brown. Cool on a wire rack until the pie crust is cool to the touch.
Reduce oven temperature to 350F.
While the pie crust is cooling, in a large saucepan, combine sugar and flour; stir in milk until smooth. Bring to a boil. Reduce heat; cook and stir 2 minutes or until thickened and bubbly.
Remove from heat; stir in butter and matcha. If clumpy, use an immersion blender to get the matcha to fully blend in.
Bake for 12 minutes -- it will still be jiggly in the middle. Transfer the pie to cool on a wire rack for another 15 minutes, then transfer to the refrigerator until fully cooled & set, another hour or two.