Preheat oven to 375°F. Place prosciutto slices on a parchment-lined sheet and bake until crisp, 8–10 minutes. Set aside to cool, then break into pieces.
In a wide skillet, heat olive oil and butter over medium heat. Add shallots with ¼ teaspoon kosher salt and cook until softened, 2–3 minutes.
Add Arborio rice and stir for 2–3 minutes, until grains are coated, lightly sizzling, and edges turn translucent.
Pour in the wine and simmer until mostly absorbed.
Add warm broth one ladle at a time, stirring often (about every 30 seconds) and allowing the liquid to absorb before adding more. Maintain medium heat (gentle simmer). Continue until rice is about ⅔ cooked, 10–12 minutes.
Stir in pumpkin purée, thyme, nutmeg, and maple syrup. Continue cooking with broth additions for an additional 12–15 minutes, until the rice is creamy and tender with just a slight bite (approximately 22–25 minutes total).
Remove from heat, stir in Parmesan, then taste and adjust with more salt and black pepper if needed.
Spoon into bowls and top with crispy prosciutto pieces, then drizzle with extra-virgin olive oil.