Preheat the oven to 400 degrees F.
Spray a 9x13” baking dish with cooking spray.
Roll out the crescent roll into the baking dish. Press it lightly into the pan to stick. The short sides will go up the sides a bit, but the long sides most likely won’t, and that’s okay. Set aside.
Heat the olive oil in a large skillet over medium-high heat.
Add the zucchini, summer squash, and red onion, and season with salt and pepper to taste.
Cook until softened, about 7-8 minutes.
Add the tomatoes, corn, and basil, and cook for another 2 minutes.
Spread the vegetables evenly on top of the crescent roll.
Sprinkle the crumbled goat cheese on top of the vegetables.
In a medium bowl, whisk together the eggs, milk, dijon mustard, salt, and pepper.
Pour the eggs on top of the vegetables and cheese.
Bake in the preheated oven for 30-35 minutes, until no longer jiggly and slightly golden brown on top.
Serve topped with additional fresh basil.