Remove pastry sheet from freezer and completely thaw. Preheat oven to 355°F.
Spray 9x13 pan with baking spray. Place pastry sheet on bottom of pan. Some of the sheet will go up against sides of pan.
Slice the zucchini into thin slices. (About 21 slices)
Slice tomatoes into about 4 slices. The larger slices in the middle of tomato cut in half. If tomatoes are very juicy, tap lightly with a paper towel. Too much tomato juice with make the pastry sheet too soggy and hard to bake.
Cut cheese slices in four.
Start with either the tomatoes or zucchini. (Whichever you have more of.)
Place three tomatoes down. Top with 3 slices of cheese.
Top with three slices of zucchini. Top with cheese.
Continue until you get to the end of the pan.
Brush top of veggies and cheese with the olive oil. Lightly salt and pepper. Sprinkle with basil.
Cover pan with foil. Bake 10 minutes. Remove foil and bake another 20-25 minutes until cheese melts and starts to become a golden color.