The layered structure that characterizes croissants is formed through a process called lamination: A relatively lean yeasted dough is wrapped around a block of butter, and then the package is rolled out and folded repeatedly to form paper-thin layers of dough separated by even thinner layers of butter. Due to increasing gluten formation, the dough becomes more difficult to roll with every turn, so we were relieved to find that three turns was sufficient to yield a light pastry made up of hundreds of delicate layers. High-protein all-purpose flour struck the right gluten balance: enough to support all that butter but not so much that we struggled with the dough. Using the right butter was important, too. The higher water content of conventional butter caused it to break up in the dough, which meant that the dough layers stuck together, resulting in less lift. Using higher-fat European butter worked much better and was worth the extra expense. Lastly, giving the dough and butter packet a couple of intense 30-minute chills in the freezer brought the two components to a more comparable consistency, making it easier to maintain distinct layers.