Bring a large pot of water to a boil. In a large, deep skillet, melt the butter in 2 teaspoons of the olive oil. Add the minced garlic and cook over moderate heat until fragrant, about 2 minutes. Add the cauliflower florets and cook over moderately high heat, stirring, just until lightly browned, about 3 minutes. Add the water, cover and cook until the cauliflower is tender, about 4 minutes. Add the heavy cream and simmer until slightly thickened, about 6 minutes. Add the crabmeat and stir gently to heat through. Season with salt and pepper and keep warm. Add salt and the remaining 1 tablespoon of oil to the boiling water and cook the pasta sheets until just tender, about 1 minute. Drain and return to the pot. Lightly drizzle the sheets with olive oil and, using 2 large spoons, toss lightly to coat. Place 1 pasta sheet on each of 4 warmed plates. Spoon the creamed crab and cauliflower onto the pasta sheets and sprinkle with half of the Parmesan cheese. Cover with the remaining pasta sheets and sprinkle with the remaining Parmesan. Serve right away.