Trim the stem end of the eggplant and zucchini. Cut both lengthwise into 1/4-inch slices using a mandoline. Sprinkle both with Kosher salt and set aside in a colander for 1 hour.

Preheat oven to 375 F. Line 2 baking sheets with parchment paper. Spray the parchment with cooking spray and place the eggplant and zucchini slices in a single layer on separate pans. Spray the slices with cooking spray. Bake for 10 minutes. Flip the slices over and bake an additional 8 minutes until soft and cooked through. Set the pans aside to cool. Increase the oven temperature to 425 F.

In a medium-sized bowl, combine the Parmesan, ricotta, lemon zest, juice, thyme leaves, and Kosher salt. Spray a baking dish with cooking spray and add enough basic sauce to cover the bottom.

On a work surface, lay down one slice of eggplant, top it with a slice of zucchini. Place a generous spoonful of the ricotta mixture at one end and roll the slices around the filling. Place seam-side down in the prepared baking dish. Repeat with other rolls.

Surround and top the rolls with remaining sauce. Top each roll with a dollop of pesto.

Bake for 20 to 25 minutes, until rolls are browning and sauce is bubbling. Cool for 5 minutes, garnish with Parmesan and serve.