1. Place all dough ingredients into the bowl of a food processor fitted with the S-blade attachment. Process for a minute or so, or until a dough forms. If necessary, add the additional tablespoon butter. Place dough into a bag, seal, and put in the refrigerator for about an hour, to chill.
2. Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius).
3. Sprinkle a sheet of Gefen Parchment Paper with flour. Place dough in the center. Cover with another sheet of parchment paper, and roll out dough into a large circle.
4. Remove the upper layer of parchment paper, and carefully spread the cream cheese in the center of the dough (in a circle), leaving at least two inches (five centimeters) for the edges. Lay a slice of tomato, then a slice or two of zucchini, and continue alternating, in a continuous circle, until the cream cheese area is covered. Place the cherry tomato slices in the very center. Sprinkle top with crushed garlic and basil ribbons. Drizzle vegetables with olive oil.
5. Carefully fold over edges, “pleating” it as you go along. Brush edges with egg wash, if desired, for a shiny look. Place parchment paper with galette on a baking sheet, and bake for 20 minutes.
6. Sprinkle with Parmesan cheese, and bake an additional 10 minutes. Let cool five–10 minutes before slicing and serving.