How to Make It
In a medium bowl, using a rubber spatula, stir the nonfat milk with the condensed milk until smooth. Add the salt, vanilla and cinnamon and stir until well combined. (The mixture will be very thick and sticky.)
Dust a work surface generously with confectioners’ sugar. Line a rimmed baking sheet with parchment paper and dust lightly with more confectioners’ sugar. Scrape the pastillas dough onto the prepared work surface. Lightly dust your hands with confectioners’ sugar and kneed the mixture a few times until smooth. Divide the dough into 3 pieces. Roll each piece into a rope about 20 inches long and 1/2 inch thick. Using a sharp knife, cut each rope into 1-inch pieces. Transfer to the prepared baking sheet and refrigerate until firm, about 10 minutes.
Using your hands, roll each pastillas into a 1 1/2-inch cylinder. Wrap each pastillas in a square of clear cellophane and twist the ends to seal.