Croissants are a laminated yeasted dough that originated in Austria in 1686. The key to producing croissants is rolling butter into the dough through multiple folds and turns, totaling 4, with rests in between to relax the gluten. Instant yeast is used and the dough is shaped into a paton, chilled, and can be frozen for later use. Croissants are rolled into triangles, proofed, and baked at 375 degrees Fahrenheit to puff the layers and ensure proper structure. Varieties include filling the dough rectangles with chocolate, ham and cheese, or other sweet or savory fillings.