Line the bottom and sides of a rectangular or square cake pan with parchment paper, greased.
Grate the frozen butter. You can also grate it before freezing to make it easier, requiring less effort.
In a large bowl, mix the flour, salt, and sugar. Add the grated butter and rub with your fingers until the mixture resembles coarse crumbs. Your dough will have a slightly granular texture like flour.
Pour the dough into the pan. Even it out and flatten it with a spoon, then place it in the freezer for 15 minutes.
Meanwhile, preheat your oven to 180°C (350°F).
After 15 minutes, bake for approx. 20 minutes. The crust should be lightly browned.