Preheat your oven to 180°C (350°F). While the oven is heating, lightly grease a baking dish with a small amount of olive oil or butter to prevent the zucchini from sticking during baking.
Wash the zucchinis thoroughly, then slice each one in half lengthwise. Using a spoon, gently scoop out the center flesh to create a “boat” shape. Be careful not to scoop too deep—leave a thin border around the edges so the zucchini holds its structure while baking.
Place the hollowed zucchini halves neatly into the prepared baking dish. Arrange them in a single layer so they cook evenly, then place them in the oven and pre-bake for about 10 minutes. This step helps remove excess moisture and prevents soggy zucchini later.
While the zucchini is pre-baking, heat olive oil in a skillet over medium heat. Add the finely chopped mushrooms and cook them slowly, stirring occasionally. Let them release their moisture and continue cooking until that moisture evaporates and the mushrooms turn slightly golden—this is where the flavor develops.
Add the minced garlic and chopped spinach to the skillet. Stir continuously for 1–2 minutes until the spinach wilts down completely and everything becomes fragrant. Make sure there’s no excess liquid left in the pan.
Remove the skillet from heat and transfer the mushroom and spinach mixture into a mixing bowl. Add the ricotta cheese, salt, black pepper, and Italian seasoning. Mix everything together thoroughly until you get a creamy, evenly combined filling.
Carefully take the zucchini out of the oven. Using a spoon, fill each zucchini boat generously with the ricotta mixture. Gently press the filling into place so it stays compact and doesn’t spill over.
Sprinkle shredded mozzarella and grated parmesan cheese evenly over the top of each stuffed zucchini boat. Make sure each one is well covered for that perfect melted, golden topping.
Return the baking dish to the oven and bake for 20–25 minutes. The zucchini should become tender, and the cheese on top should be fully melted, bubbly, and lightly golden.
Remove the dish from the oven and let the zucchini boats rest for a few minutes before serving. This allows the filling to set slightly, making them easier to serve while keeping their shape intact.