Baked Shells with Winter Sqush

I first had this recipe at our friends Dorian and Marianne's house and before I could finish eating it I was asking for the recipe...I don't know if that was a compliment or totally out of line, but either way I got the recipe and have made it multiple times since.  I like to think of it as a grown up version of traditional macarroni and cheese but with much fewer calories!  Even if you've never been a fan of or even tried butternut squash, please promise me you will make this recipe and try it...I promise it won't let you down!  And if you have kids that love mac'n cheese then I would recommend introducing them to this delicious recipe, I think they'll even approve!

INGREDIENTS:
Butter, for baking dish
4 tablespoons olive oil
2 large onions, halved and thinly sliced
Coarse salt and ground pepper
2 teaspoons chopped fresh rosemary leaves
1 pound small pasta shells
2 packages (10 ounces) frozen winter squash puree, thawed
1 cup grated Parmesan cheese
3 slices crusty baguette, cut into 1/4-inch cubes (1 1/2 cups)
 
DIRECTIONS:
 
1.Preheat oven to 400 degrees. Butter a 9-by-13-inch baking dish. Heat 3 tablespoons oil in a large skillet over medium-low heat. Add onions; season with salt and pepper. Cover; cook until onions are soft and release liquid, 15 minutes. Uncover; raise heat to medium. Cook, stirring, until onions are browned, 20 to 25 minutes. Stir in 1 teaspoon rosemary.
2.Meanwhile, cook pasta in large pot of boiling salted water 2 minutes less than package instructions suggest. Drain, reserving 1 1/2 cups cooking water. Return pasta to pot.
3.Stir squash and reserved pasta water into onions; simmer 2 minutes. Toss squash mixture and 1/2 cup Parmesan with pasta. Transfer to prepared dish.
4.Combine bread cubes with remaining Parmesan, rosemary, and oil; season with salt and pepper. Top pasta with bread cubes; bake until golden brown, 10 to 15 minutes.
 

******* For those of you wondering where to buy winter squash, check the organic frozen section of your grocery store.  I use Winter Squash Puree by Cascadian Farm.  If your grocer doesn't carry it you can request it and they'll add it to their inventory.