Mingari-Spiced Owlbear Milk

Ingredients

• ½ cup old-fashioned oats
• 1 cup water
• 4 cups milk (see Cook's Note), plus more as needed
• 2.5 tablespoons granulated sugar
• 1.5 tablespoons light brown sugar
• 1 pinch kosher salt
• 3 cinnamon sticks, plus ground cinnamon for sprinkling

Instructions

1. In a dry medium saucepan over medium heat, toast the oatmeal, stirring constantly, until very fragrant, 4 to 5 minutes (take care to avoid burning it). Remove from the heat, add the water (it will spatter), and gently swirl the pan. Add the milk, both sugars, salt, and cinnamon sticks and stir to mix. Return the pan to medium heat and bring to a low, steamy simmer, stirring often, about 7 minutes. Adjust the heat to low and continue to simmer, stirring occasionally, until cooked through and soft, about 5 minutes. (If the mixture threatens to boil over, remove the pan from the heat until the foam recedes and then continue.) Remove the pan from the heat and let the mixture cool to room temperature. Scrape into a large wide-mouth jar with a tight-fitting lid, seal, and refrigerate until well chilled, at least 4 hours or up to 24 hours.
2. Remove the mixture from the refrigerator. Remove and reserve the cinnamon sticks. Scrape the mixture into a blender (keep the jar handy) and blend on high speed until as uniform and smooth as possible. Strain through a fine-mesh strainer back into the jar, working it with a flexible spatula until just a couple of teaspoons of oat paste remain. Discard the paste, return the cinnamon sticks to the jar, cover, and refrigerate until cold, about 1 hour.
3. Remove the jar from the refrigerator and vigorously shake it. Adjust the consistency of the mixture, if desired, by adding up to ¾ cup milk, ¼ cup at a time, shaking after each addition to blend. Remove the cinnamon sticks and pour the milk into glasses (over ice, if desired). Sprinkle each with ground cinnamon before serving.