Heat the olive oil in a skillet over medium heat. Add the pancetta and sauté until beginning to brown. Add the onion and continue cooking, 2 minutes.
Add the garlic and cook until the onion is soft and translucent and the garlic is fragrant, 1 to 2 minutes longer. Remove from the heat and allow to cool.
Place the scallops, parsley, breadcrumbs, egg, 1/4 teaspoon salt and a few grinds of black pepper in a mixing bowl. Add the pancetta mixture and combine gently.
Loosely stuff the mixture into the squid tubes to about 3/8-inch from the opening and fasten closed with a toothpick. Do not pack or overstuff.
Coat a shallow casserole large enough to hold the squid tubes side by side with nonstick spray.
Spoon a thin layer of marinara into the bottom of the prepared dish. Arrange the squid in a single layer and spoon 1 to 1-1/2 cups of marinara on top. Cover tightly with aluminum foil and bake for 30 minutes.
To serve with pasta:Cook 8 ounces of linguine or spaghetti according to the package directions and drain.
The squid will give off some liquid while they bake, adding fabulous flavor to the sauce in the casserole. Add this to the remainder of your marinara and toss with the cooked pasta. Plate individual servings and top with squid.
Tips for Making This Recipe
About the bay scallops: If you can't get or don't care for bay scallops, feel free to replace them with sea scallops or 1/4 lb of peeled and deveined shrimp.How to make soft, fresh breadcrumbs: Tear a few thick slices of crusty Italian or French bread into 1-inch pieces and add them to the work bowl of a food processor. Pulse until coarsely chopped.