Bring a large pot of water to a boil, salt it, add the penne and cook until al dente, about 7 minutes. Drain, reserving a ladleful of the starchy cooking water.
While the pasta is working, in a medium Dutch oven, bring 1 1/2 cups water to a boil; salt it. Add the cauliflower, cored side down; cover and cook until just tender, 8-10 minutes. Remove the cauliflower with a slotted spoon, spider or tongs and let cool slightly. Cut into bite-size florets.
Meanwhile, in a large skillet, heat the EVOO, four slow turns of the pan, over medium heat. Add the anchovies to melt into the EVOO. Stir in all the chilies, celery, onion, bell pepper and garlic; season with salt, pepper and the oregano. Cook for 6-7 minutes. Stir in the reserved starchy cooking water, the parsley and the lemon juice. Stir in the pasta and cauliflower and toss to combine. Turn off the heat.
In a large skillet, heat the peanut oil over high heat. Add the seafood and cook until firm and opaque; season with salt, pepper and the Old Bay. Add the vermouth and deglaze.
Add the seafood to the pasta and toss. Serve hot or refrigerate and serve cold (if serving cold, drizzle more EVOO on top and sprinkle with a little more finely chopped garlic and fresh herbs).