Add flour, butter and salt into a food processor. Pulse the machine on and off until the mixture is crumbly. A few pea-sized bits of butter are ok. Slowly add the water with the machine running just until the dough forms a ball. Wrap the dough in plastic film and flatten. Chill for at least 30 minutes.
Prepare the tarts:
Preheat the oven to 375 degrees F. Line a baking sheet with parchment paper.
Toss the zucchini and olive oil together in a small bowl. Combine the ricotta, salt, garlic, and basil in a separate bowl (it's best to let this mixture sit for at least 20 minutes so the garlic and basil flavors absorb into the cheese).
Toast the pine nuts in the oven until golden brown and fragrant, approximately 5 minutes.
Remove the dough from the refrigerator and cut into 4 or 6 even pieces (4 will give you more wiggle room but 6 galettes is the final goal). Leave one piece out and return the other sections to the fridge so they remain firm.
On a barely floured clean surface, roll out the dough as thinly as possible. Place a 3 1/2 inch round cookie cutter in the center without actually cutting the dough (a larger or smaller cutter is fine but will effect the yield). Slice off some of the excess dough, leaving approximately 1 inch of extra dough. If you only cut 4 pieces, save the excess dough to roll into 2 more sections.
Add 1 heaping tablespoon of the ricotta mixture into the cookie cutter and spread evenly. Grate some Parmigiano Reggiano on top. Fan out several slices of the zucchini in a circular pattern to fill the space. Top with more Parmigiano Reggiano and some freshly ground black pepper. If using, sprinkle a bit of finishing salt on top. Tightly fold the excess dough on top of the zucchini to form the galette. Gently press down to flatten the top.
Repeat this process with all of the dough and ingredients. Chill the galettes for 15 minutes and then bake until the dough is golden on top, approximately 25 minutes.
Garnish with toasted pine nuts before serving.
The dough can be prepared and chilled up to several days in advance. A cookie cutter is not necessary for preparing the tarts but will help ensure they are evenly sized.