Fill a large pot with water (~3-4 quarts) and bring to a boil over high heat. Add a generous amount of salt (~1 tbsp) and the greens. Cook for 2 minutes, submerging them into the water, then use tongs to transfer greens to a cutting board, shaking off excess water.
Add the pasta to the boiling water and cook according to the package instructions. Reserve 1 cup of pasta water, then drain.
While you wait for the water to boil/pasta to cook, in a large skillet over medium-low heat, add 2 tablespoons butter, olive oil, garlic, and red pepper flakes and cook for 1 minute or until butter has melted and is bubbling slightly and garlic is fragrant, stirring occasionally (see garlic note).
Stir in the zucchini, basil, and salt. Increase the heat to medium-high and cook for 10-15 minutes, stirring occasionally, or until the liquid has been cooked out, zucchini is beginning to stick to the pan, and is soft and “jammy” in texture.
Once the greens have cooled enough to handle, form into a tight log, squeeze out any excess water, then thinly sliced the greens (keeping it in a tight log while you slice).
Add pasta back to the pot along with the zucchini mixture, greens, ½ cup pasta water, remaining 2 tablespoons butter, and parmesan cheese. Stir vigorously to combine for about 1-2 minutes, or until the butter has melted and a glossy sauce has formed. If it’s looking dry, add a splash of more pasta water and keep stirring. Stir in the lemon.
Serve topped with marinated beans (if using), a dollop of ricotta (if using), more parmesan cheese, basil (if you have any more), and black pepper.