· Cooking spray, olive oil, or coconut oil· 2 tablespoons unsalted butter, divided· 1 1/2 cups steel-cut oats· 1 (15-ounce) can pumpkin purée· 1 teaspoon ground ginger· 1/2 teaspoon ground nutmeg· 1/4 teaspoon ground cloves· 4 cups water· 2 cups whole milk· 1/4 cup maple syrup· 1 (3-inch) cinnamon stick· 1 teaspoon vanilla extract· 1/4 teaspoon salt· For serving: heavy cream, ground cinnamon, and additional maple syrup (optional)
Step 1Coat the bottom and sides of a 4- to 6-quart slow cooker with cooking spray, olive oil, or coconut oil.Step 2Melt 1 tablespoon of the butter over medium-high heat in a large saucepan or Dutch oven. Add the oats and stir frequently until lightly toasted, about 3 minutes. Push the oats up to the side of the pan and melt the remaining tablespoon of butter in the center of the pan. Add the pumpkin purée to the center of the pan and cook without stirring for 1 minute. Add the ginger, nutmeg, and cloves into the purée and cook, stirring occasionally, until the purée darkens slightly and the raw smell disappears, 3 to 4 minutes more.Step 3Transfer the mixture to the prepared slow cooker. Add the water, milk, maple syrup, cinnamon stick, vanilla, and salt and stir well to combine.Step 4Cover the slow cooker and cook on the LOW setting for 8 hours. When finished, much of the pumpkin purée will have separated from the oats — don't panic! Stir well with a wooden spoon to recombine everything, and remove the cinnamon stick before serving. Spoon the oatmeal into bowls and finish with a splash of heavy cream, a dusting of ground cinnamon, and a drizzle of maple syrup, if desired.