Preparation
Using a sharp knife, carefully cut enough kernels off the corn cobs to make 3 to 3 1/2 cups. Then scrape the cobs with a knife to remove all their milk.
Place 2 1/2 cups of the corn in a blender along with 2 cups of the water and puree well.
Strain the pureed corn through a sieve into a medium saucepan and discard the solids. Stir in the remaining corn kernels, 1/3 cup sugar and salt.
Bring the liquid to a boil over medium-high heat, then reduce heat to low and simmer for 5 minutes, or until lightly thickened.
If the atol doesn't thicken to a creamy consistency, mix the cornstarch with a little cold water and whisk into the simmering liquid until it is just thick enough to coat a spoon.
Pour the hot atol into mugs or small bowls, sprinkle with a little cinnamon and serve hot with a spoon to scoop up the corn kernels.
