Preheat your oven to 400°F (200°C).
In a large skillet, heat olive oil and sauté garlic until fragrant.
Add the tomato passata, oregano, salt, and pepper. Let it simmer for about 10 minutes.
Meanwhile, cook the gnocchi in salted boiling water until they float to the surface, then drain.
Toss the gnocchi into the sauce, coating them well.
Transfer everything to a baking dish, scatter mozzarella cubes, and sprinkle Parmesan on top.
Bake until the cheese melts and turns golden, about 15–20 minutes.
Top with fresh basil and serve hot.