1️⃣ In a large pot over medium-high heat, heat the olive oil until shimmering, then add the onions. Cook the onions until they are starting to soften and become translucent, 3-5 mins, then add the zucchini, garlic, salt, and pepper. Cook for 5-7 mins until the zucchini is starting to become tender, then add the water.
2️⃣ Bring to a boil over high heat, then turn down to a simmer, cover, and cook for 10-15 mins until the zucchini is tender.
3️⃣ Carefully transfer the soup to a blender and add the fresh basil leaves. Blend until completely smooth and cover to keep warm.
4️⃣ Make the olive oil fried bread (optional): Coat the bottom of a large skillet with a thin layer of olive oil over medium heat. Once the oil is shimmering, place the bread in the pan, press lightly to coat, then flip immediately and cook until deeply golden brown, 1 to 2 mins. Flip the bread and cook until deeply golden brown on the other side, 1 to 2 mins more. Slice the bread in half down the middle.
5️⃣ Ladle the soup into bowls and top with a drizzle of high quality olive oil and a generous amount of freshly grated parmesan. Serve with olive oil fried bread on the side, if you like, and enjoy!
