Farfalle, orecchiette, or gemelli can be substituted for the campanelle. If the pasta seems too dry, stir in up to ¼ cup of hot water.
Cook bacon in 12-inch skillet over medium-high heat until crispy, 5 to 7 minutes. Add panko and ¼ teaspoon pepper and cook, stirring frequently, until panko is well browned, 2 to 4 minutes. Transfer panko mixture to bowl and wipe out skillet.
Heat 5 teaspoons oil in now-empty skillet over medium-high heat until shimmering. Add cauliflower and 1 teaspoon salt; cook, stirring occasionally, until cauliflower is crisp-tender and browned in spots, 10 to 12 minutes. Remove pan from heat and cover to keep warm.
Heat remaining 1 teaspoon oil in Dutch oven over medium heat until shimmering. Add onion, thyme, and ½ teaspoon salt; cook, stirring frequently, until onion has softened, 4 to 7 minutes. Increase heat to high, add pasta, broth, and wine, and bring to simmer. Cook pasta, stirring frequently, until most of liquid is absorbed and pasta is al dente, 8 to 10 minutes.
Remove pot from heat; stir in parsley, lemon juice, and cauliflower; and season with salt and pepper to taste. Serve, passing panko mixture and lemon wedges separately.
