Softened or cold butter for shortcrust pastry?
A lot of people tell you to use well chilled butter for the best flaky shortcrust pastry and shortbread. They advise to cut it in with knives and work quickly in order to keep the temperature down.
Not so: my tried and tested rule is soft - chilled - soft - chilled.
That means using softened butter to make the pastry which you then chill properly before processing further. For that, it needs to return to room temperature, otherwise it will crack horribly when you try to roll it out. Cut and shaped pastries will then go back to the fridge briefly before baking.