In a cast-iron skillet or oven-proof pan, drizzle the olive oil and add the minced garlic. Cook for a couple of minutes on medium heat until it starts to sizzle.
Pour the crushed tomatoes and add about half can of water to the skillet. Bring to a simmer then turn the heat to low.
Add the basil leaves to the tomato sauce and season with salt to taste. Simmer for about 30 minutes to 1 hour. If necessary, add a bit of water.
Bring a large pot of salted water to boil and turn on the oven to 450°F (230°C) with broiler. Add the shredded mozzarella balls to the tomato sauce and mix. Turn off the heat.
Toss the gnocchi in the boiling water and cook until they rise to the surface. Then drain with a skimmer and toss them in the tomato sauce. Mix well until they're all fully coated.
Sprinkle the Parmesan cheese on top and move to the oven for 5-10 minutes until golden brown on top and bubbling.
Notes
Place any remaining gnocchi in an airtight container and refrigerate for up to 3 days. Or freeze for up to 2 months.