Butternut Squash Pasta Bake

I love butternut squash.  The affair began at the beginning of this summer, when I experienced the Best Risotto Ever (at Bar Italia-- squash, grape tomatoes, and fiddlehead fern-- it still haunts my dreams).  Incidentally, that was the same time I fell in love with risotto, but that's neither here nor there.  I concocted this guy when I had half a roasted butternut squash lying around from a previous recipe.  Enjoy.

1 box tube shaped pasta
1 butternut squash (pick out a good one)
1 sweet onion, chopped
1 Tbsp. Sriracha
1 Tbsp. tomato paste
1 lb. thick cut bacon, sliced into 1/2" pieces
1-15.5 oz container part skim ricotta
1/2 bag Italian blend cheese
Bechamel sauce (below):
        1/2 cup butter
        3/4 cup flour
        4 cups warm 2% milk
        1/2 cup mozzarella
        salt, pepper, garlic powder to taste

1. Preheat oven to 400 F.  Slice the squash in half lengthwise, scoop out the seeds.  Brush the cut sides with olive oil.  Place squash cut side up on a baking sheet.  Roast for 45-60 minutes, until soft.  Let squash cool, then peel.
2. Cook bacon over medium high until crispy.  Remove with a slotted spoon and drain on paper towel.
3. Reserve about a tablespoon of bacon grease, dispose of the rest.  Saute onions in bacon grease over medium high until caramelized.
4. Puree squash, onion, Sriracha, and tomato paste in food processor.
5. Cook pasta until al dente.
6. Prepare Bechamel sauce:  In a saucepan, melt butter over medium.  Add flour and stir, making a paste.  Cook for 3 minutes, stirring frequently.  Whisk in milk slowly.  Cook for 5 minutes, stirring constantly.  Add cheese, season to taste.
7. Preheat oven to 375 F.
8. In a 9x13" baking dish, layer: pasta, sauce, squash puree, ricotta, bacon.  For last layer: pasta, sauce, Italian cheese blend, bacon.  Bake 30 minutes.

Not a looker by any stretch, but it feels cozy in your belly, which is high priority for me around finals.  Also, you'll almost certainly have leftover Bechamel sauce, and maybe squash and ricotta.   Finally, this makes an unreasonable amount of pasta.  You will eat for days.  Feel free to halve this recipe if you can come up with something else to do with the other half-squash.