Place the butter* and the sugar in a bowl and mix until it becomes a paste.*Make sure the butter is soft (I cut it into cubes and let them at room temperature for half an hour before using it).
Add the egg, flour and mix until the dough easily forms a ball.
Wrap the dough (I use saran wrap). Cool in the refrigerator for at least an hour (or 30 minutes in the freezer). You may also let it sit in the fridge overnight.
Remove the dough from the refrigerator and let it sit at room temperature for 10 minutes, so it softens just enough to make rolling a little bit easier. Meanwhile, grease the pie form and preheat oven to 356°F (180°C).
Place the dough on a lightly floured surface and roll it out until it’s big enough to cover your pie plate. (I personally find it more convenient to roll the dough on baking paper or plastic wrap)
Place the dough in the greased pie form. Trim the edges and seal any cracks with the excess dough.
Prick the dought with a fork several times.Back the tart crust for 15-20, or until golden (make sure not to overdo it).You may want to use pie weights to avoid the crust from shrinking (as you may see from my pictures, I didn’t use weights).
Make matcha almond filling
(You can make the filling while you bake the pie crust)Combine the butter, sugar, eggs, almond meal and matcha powder.
Fill the baked pie crust with this almond cream. (It’s best if the crust is at room temperature, but I don’t wait and do it while still hot)Top with roughly cut walnuts and then push them down lightly.
Bake for 20 minutes at 347°F (175°C)Allow to cool at room temperature before topping with the matcha cream.
Make matcha mascarpone cream
(It’s best to whip the matcha cream when the pie crust and almond filling are already at room temperature and ready to decorate).Combine whipping cream, sugar and matcha and whisk until peaks form.Then add the mascarpone and combine until homogeneous.
Mound onto the cooled pie and almond filling. If desired, sift some matcha on top to decorate.