Baked Autumn Penne Casserole

My sweet cousin posted a vegan pumpkin baked ziti recipe on my Facebook wall, suggesting I try it sometime. As I always do, I looked over the ingredients and instructions and realized I had to do some modifications. The result was delish! It does not taste like pumpkin at all. It's a creamy pasta dish with aromatic seasoning. My husband gobbled it up and asked for seconds!
 I am calling this "Baked Autumn Penne Casserole".

8 oz. whole wheat penne pasta, cook until al dente
2 large shallots, minced
8 oz. baby bella (cremini) mushrooms, sliced
¼ cup whole wheat flour or whole wheat pastry flour
2 ½ cups unsweetened non-dairy milk (soy, almond or cashew works best)
1 cup pumpkin puree
¼ cup vegan parmesan cheese
¼ t. rubbed (ground) sage
pinch of nutmeg
salt/pepper to taste
¼ cup whole wheat bread crumbs

NOTE: If you do not have a very large skillet, make the sauce and pour it over the noodles in the casserole dish rather than adding the pasta to the skillet first. Either way works fine!

Preheat oven to 350 degrees F.
Boil the pasta according to package directions, but only until al dente. When it reaches al dente, drain and set aside.
While the pasta is cooking, steamfry the shallots in veggie broth (in a VERY large skillet) until tender (about 5 minutes) and golden brown.
Add the sliced mushrooms and cook until tender and moisture has evaporated.
Sprinkle in the flour over the shallots and cook for 1 minute. A
Add the non-dairy milk slowly into the skillet and stir well or whisk until incorporated.
Add the pumpkin puree and continue stirring  until incorporated.
Add rubbed sage, nutmeg, salt and pepper to taste.
Cook over medium heat stars to thicken, stirring often.
Stir in the vegan parmesan cheese.
When the sauce has thickened (to the texture of alfredo sauce), add the cooked pasta and stir well to coat all pieces.
Place the sauce-coated pasta into a casserole dish (slightly smaller than a 13x9 if possible).
Top the casserole with whole wheat bread crumbs.
Bake covered (with foil) for 10 minutes. Uncover and bake an additional 10 minutes or until the top is lightly browned.