Crème brûlée was first mentioned in France in the late 17th century, and may have been derived from the similar crema catalana made in Roussillion and just south of the border. It’s a custard made of cream, sugar and egg yolks, traditionally flavoured with vanilla, baked in ramekins in the oven in a bain marie, and finished with a deep brown crust of sugar caramelized on top—these days with a butane torch.
Crema catalana is made with milk rather than cream, which is the only real difference.
In the 20th century crème brûlée was revived in the USA; it ricocheted back to France, where it’s become one of the most popular desserts.
Image by star5112 - JOH_1417 auf flickr