Fill a large pot with lightly salted water and bring to a rolling boil over high heat. Once the water is boiling, stir in the bow tie pasta and return to a boil. Cook the pasta uncovered, stirring occasionally, until the pasta has cooked through, but is still firm to the bite, about 12 minutes. Reserve 1/2 cup of pasta cooking water, and drain the farfalle well in a colander set in the sink.
While the farfalle are boiling, mix together the ricotta, mascarpone, and Parmesan cheeses in a large serving bowl, and stir in the lemon peel and basil until the mixture is well combined.
Heat olive oil in a large skillet over medium heat, and cook and stir the zucchini and garlic until the zucchini are tender but still bright in color, about 8 minutes. Stir about 1/4 cup of the reserved pasta cooking water into the cheese mixture and mix until smooth; add the hot drained pasta and cooked zucchini, and lightly toss with the sauce. Season with the salt and pepper. If mixture is too thick, add a little more pasta cooking water, 1 tablespoon at a time, until the sauce is the desired thickness.
