Preheat oven to 350°F. Coat a 9-by-13-inch baking dish with cooking spray.
Heat 1 teaspoon oil in a large nonstick skillet over medium heat. Add prosciutto; cook, stirring, until crispy, about 5 minutes. Drain on a paper towel.
Wipe out the pan and heat the remaining 2 teaspoons oil over medium-high heat. Add onion, fennel and shallot and cook, stirring, until softened and beginning to brown, 6 to 8 minutes. Add sage, thyme and rosemary and cook, stirring, for 1 minute more. Transfer everything to a large bowl and gently stir in bread, pears, parsley, hazelnuts and the prosciutto. Add broth; toss to combine. Season with salt and pepper. Spoon the stuffing into the prepared baking dish; cover with foil.
Bake for 40 minutes; remove the foil and bake until the top is beginning to crisp, 25 to 30 minutes more.
To toast chopped nuts & seeds: Cook in a small dry skillet over medium-low heat, stirring constantly, until fragrant and lightly browned, 2 to 4 minutes.Ingredient note: If you don't have stale bread ready to use, spread the baguette cubes on a baking sheet and toast at 250°F until crisped and dry, about 15 minutes.