We love the texture of this smooth soup with some rice mixed in, but it is a delicious fall soup without, as well.
In a medium saucepan, boil 3 cups water. Add brown rice and reduce heat to low, cover, and simmer until rice is cooked and water is absorbed, 40-45 minutes. Remove from heat. Remove lid and place a clean kitchen towel over top of pot. Place lid over towel and allow to cool to room temperature. Once cooled, fluff with a fork.
Place squash on a baking sheet and toss with olive oil. Season with salt and pepper. Roast for 35-40 minutes, turning once, until lightly browned on all sides and softened.
Allow squash to cool, and transfer to a blender along with 2 cups of stock and purée until smooth (do this in batches if necessary). Add more stock if needed. Transfer soup to a large saucepan and add remaining stock. Allow to simmer for about 10 minutes, until warmed through.
In a small bowl, combine yogurt and maple syrup.
Divide rice among serving bowls, followed by soup. Top each with a spoonful of maple yogurt. Top with squash seeds (if using), a drizzle of additional maple syrup, and serve warm.