Toss the zucchini and summer squash with salt in a large bowl and let it sit for 20 minutes to draw out moisture. Drain the squash and wipe away the residual salt and moisture thoroughly with paper towels—this prevents the finished dish from becoming watery.

Boil a large pot of salted water and cook the farfalle until al dente. Reserve 1/2 cup of the cooking water, then drain the pasta and return it to the pot.

Heat oil in a large skillet over medium-high heat until shimmering. Add half of the squash in a single layer and cook without stirring until lightly charred, about 5 minutes. Transfer to a bowl and repeat the process with more oil and the remaining squash.

Reduce the heat to medium and add the remaining oil, garlic, and red pepper flakes. Cook until the garlic is fragrant and just beginning to golden.

Stir the browned squash, tomatoes, basil, pine nuts, and balsamic vinegar into the skillet. Toss over medium heat until the tomatoes are slightly softened, about 2 minutes.

Combine the vegetable mixture with the cooked farfalle. Add the reserved pasta water as needed to create a light sauce that coats the noodles, then season with salt and pepper to taste.

Serve immediately with a generous dusting of grated Parmesan.