For the butternut squash puree: Preheat the oven to 350 degrees F.
Spread the squash out on a baking sheet and sprinkle with the oil, salt and pepper. Roast until tender, 25 minutes; allow to cool slightly. Transfer to a food processor and pulse until smooth. Measure out 1 1/2 cups puree.
For the mac and cheese: Cook the pasta according to the package directions. Drain, reserving 1 cup of the pasta water, and transfer the cooked pasta back into the hot pot it was cooked in.
Meanwhile, melt the butter in a large saucepan. Sprinkle in the flour and cook, stirring constantly, for 1 minute. Whisk in the milk and simmer until thickened; add the onion powder, salt, ground mustard and cayenne. Stir in the Cheddar, pecorino and 1 1/2 cups squash puree and cook until the cheese is melted. Pour the cheese sauce into the drained pasta and mix well. Slowly incorporate the reserved pasta water, mixing well, using about 3/4 cup depending on desired creaminess.
Spray twelve 6-ounce ramekins with nonstick cooking spray; fill with about 3/4 cup of the pasta mixture and place on a large baking sheet.
For the topping: Put the bread in a food processor fitted with a steel blade and pulse until the bread is in fine crumbs. Mix the breadcrumbs with the Parmesan and sprinkle some of the mixture over each portion of pasta; drizzle each serving with a teaspoon of canola oil. Bake until the crust becomes golden and crispy, 12 minutes. Garnish with chopped parsley and serve immediately.