What cuboid viennoiserie uses the same layered dough as a croissant and contains dark chocolate?

What cuboid viennoiserie uses the same layered dough as a croissant and contains dark chocolate? Pain au chocolat.

Pain au chocolat is a French viennoiserie made from yeast-leavened laminated dough. Butter is folded into the dough repeatedly, creating thin alternating layers that puff and separate during baking. Unlike a croissant, which is shaped into a crescent, pain au chocolat is generally formed as a small rectangular or cuboid pastry. One or two pieces of dark chocolate are enclosed in its center.

The pastry is closely associated with French bakeries and is commonly sold beside croissants, often warm from the oven. Its name literally means “chocolate bread,” although it is a flaky breakfast pastry rather than ordinary bread. Regional names vary: chocolatine is common in southwestern France and Quebec, while couque au chocolat is used in Belgium.

A common mix-up is calling it simply a “chocolate croissant.” That English-language label describes its croissant-style dough, but the shape is distinct. A filled crescent-shaped croissant may contain chocolate, whereas pain au chocolat traditionally remains rectangular.