Preheat the oven to 425 degrees F.
Line 2 large baking sheets with aluminum foil and lightly grease with olive oil. Arrange some of the eggplant, zucchini, and yellow squash slices in a single layer on the sheets, slightly overlapping them. Brush with olive oil and lightly season with salt and pepper. Bake until soft and just golden around the edges, 8 to 10 minutes. Remove from the oven and transfer to a plate to cool. Repeat with the remaining vegetable slices.
In a large bowl, combine the goat cheese with the basil, parsley, and extra-virgin olive oil. Season, to taste, with salt and pepper and mix well.
In a 6-cup terrine (12 by 3 by 3 inches), arrange the eggplant slices crosswise over the bottom and up the sides, overlapping the slices to completely cover the terrine. The ends of the slices should overhang the sides of the terrine. Top the eggplant with thin layers of red bell pepper, zucchini, yellow squash, spinach, and yellow bell pepper. Crumble a layer of the goat cheese mixture on top of the yellow bell pepper, and repeat the layering with the remaining vegetable slices. Bring the overhanging eggplant slices up over the terrine. Wrap the terrine loosely in plastic wrap. Top with an equal-size terrine or a piece of cardboard wrapped in aluminum foil. Place a brick or heavy pot on top of the terrine and refrigerate for at least 8 hours or for up to 24 hours.
Remove the terrine from the refrigerator. Remove the weight and unwrap. Slice with a very sharp knife and serve 1 thick or 2 thin slices per person with Sun-Dried Tomato Sauce and toasted croutons.
In the bowl of a food processor, combine the sun-dried tomatoes, balsamic vinegar, garlic, salt, crushed red pepper, and black pepper and puree on high speed. With the motor running, gradually add the olive oil through the feed tube and process until well combined. Pour into a container until ready to serve.
Yield: about 2 cups