In a large skillet, melt the butter. Add the pancetta and cook over high heat, stirring frequently, until browned and crisp, about 6 minutes. Add the garlic and crushed red pepper and cook until fragrant, about 30 seconds. Add the squash, season with salt and cook until dry, about 5 minutes. Stir in the cheese and sunflower seeds, transfer to a bowl and serve right away.