Preheat oven to 400 degrees
Line a rimmed baking sheet with parchment paper and lay evenly spaced bacon strips on it
Place pan in oven and bake for 15 minutes, then open oven to check bacon
Remove any strips that are done and return pan to oven to finish cooking bacon, checking every 2-3 minutes
Drain bacon on paper towels
Trim sprouts and cut in half, and place on the baking pan in the bacon grease
Toss the Brussels sprouts around to coat and season with salt and pepper
Place corn, still in husk, on baking sheet with Brussels sprouts
Place vegetables in 400 degree oven and cook for 20-30 minutes, until sprouts begin to char
While sprouts are cooking, saute the onion in butter and olive oil over medium heat until golden
Push onions to the edge of skillet and add mushrooms
Increase heat to medium high and quickly saute mushrooms until golden
Drain sprouts on paper towels and set corn aside to cool
Cook pasta in boiling water until just al dente, about 3 minutes
Drain pasta, reserving a little pasta water
Put drained pasta into a greased baking dish, pour pesto sauce over all and toss to coat
Break off tough ends of asparagus, rinse and wrap in a kitchen towel
Microwave asparagus for 1 minute, cool and cut into 1 inch pieces
Add mushrooms, onions, asparagus to pasta in dish
Cut corn from cobs, break bacon into 1 inch pieces, and add to pasta dish
Add sprouts and 1/2 of the Parmesan cheese to dish and gently toss
Mix alfredo sauce with about 1/4 cup reserved pasta water, stirring until smooth
Pour sauce over vegetables and pasta and gently fold ingredients into the sauce
Top casserole with remaining Parmesan, cover, and refrigerate
Bake covered at 350 degrees for 30 minutes, then uncover and continue baking for 10-15 more minutes until bubbling
Garnish with basil leaves and additional Parmesan if desired