Place a baking sheet in the oven. Preheat the oven to 450°F (leave the pan in the oven as it heats).

In a large bowl, toss together the broccoli and cauliflower florets with 2 tablespoons oil. Season with salt and pepper to taste. Arrange the vegetables in a single layer on the hot baking sheet; arrange the Meyer lemon slices around the vegetables. Bake at 450°F until the vegetables are starting to brown and are crisp-tender, about 15 minutes.

Meanwhile, fill a Dutch oven with water and salt the water liberally; bring to a boil. Add the pasta and cook according to package directions for al dente. Reserve 1/2 cup of the cooking liquid. Drain.

Melt the butter in the same Dutch oven over medium-high heat. Cook until browned and very fragrant, about 3 minutes. Add the remaining 2 tablespoons of oil, garlic, and Aleppo pepper; cook, stirring constantly, 30 seconds. Remove from the heat and add the heavy cream, stir to incorporate. Add the pasta, salt, and black pepper. Gently stir in the roasted vegetables and lemon wheels. Stir in 1/4 to 1/2 cup reserved cooking liquid to reach desired consistency. Top with zest, cheese, toasted pine nuts, basil leaves, and a sprinkling of Aleppo pepper if desired .