Blueberry Slow-Cooker Oatmeal

Ingredients: 1 cup steel-cut oats 4 cups water or milk (or a combination of both) 1 cup fresh or frozen blueberries 1/4 cup maple syrup or honey 1 teaspoon vanilla extract 1 teaspoon ground cinnamon 1/4 teaspoon salt Optional toppings: extra blueberries, chopped nuts, a drizzle of honey, or a dollop of yogurt