Heat the oven to 425°F (218°C).
Mix flour and salt in a big bowl.
Cut butter into small pieces, mix into the flour.
If you like, add an egg and 1/4 cup of cold water; mix into a dough.
Roll the dough into an 8-inch square on a floured surface.
Fold it like a letter, do this three times.
Cover the dough, put it in the fridge for 30 minutes.
Roll out the cold dough into an 8-inch square.
Cut it into the shapes you want, place on a baking sheet with parchment paper.
Bake for 12-15 minutes until it's golden and flaky. Let it cool before you eat it.