The traditional Mexican hot drink made from masa is Atole.
Atole is a warm, thick beverage of Mexican and broader Mesoamerican origin, traditionally prepared by cooking corn masa with water or milk. Common additions include piloncillo, cinnamon, vanilla, fruit, or other flavorings. Its texture can range from a pourable drink to a thin porridge, depending on the amount of masa used.
The name is linked to Nahuatl ātōlli, and the drink has pre-Columbian roots. Maize was central to Mesoamerican foodways, so atole served as both nourishment and a culturally important everyday drink. It is especially associated with tamales, Day of the Dead observances on November 2, and Las Posadas during the Christmas season.
Champurrado is the most important neighboring term to know. It is a chocolate-based type of atole, usually made with masa, cacao or chocolate, cinnamon, and piloncillo. Thus, champurrado can fit a broader description of a masa-based hot drink, but “atole” is the standard answer when the question does not specify chocolate.
Atole also has regional versions made with blue corn, fruit, rice, or toasted cornmeal.