The Mexican flavoring comes from the addition of cinnamon and orange liqueur. You may eliminate these ingredients or substitute a flavored extract for the liqueur. Either way, these make a terrific summer dessert.
Combine first five ingredients in medium saucepan. Place pan on medium- to medium-high heat; whisk in milk until smooth. Cook, stirring almost constantly, until mixture thickens, about 10 minutes. Cook 1 minute longer, then stir in chocolate and liqueur. Pour into molds; freeze 4 hours or overnight.