Preheat oven to 350° F.
Scoop the seeds (but not the flesh) out of each zucchini, then drizzle with a little oil, sprinkle with a little salt and pepper, then put on a baking sheet cut-side up and bake for 10-15 minutes.
In a large frying pan, cook the sausage and onion, stirring frequently, until the sausage is crumbly and fully cooked and the onion is translucent.
Add the garlic, tomatoes, cheese, basil, and 1/4 teaspoon salt to the sausage. Mix well. Let the flavors come together over medium to medium-high heat for a few minutes.
Take the zucchini out of the oven, and fill each zucchini with the sausage-cheese mixture. Top each zucchini boat with an extra sprinkling of cheese, and 1 teaspoon of panko breadcrumbs.
Return to oven and bake uncovered for an additional 10-15 minutes or until zucchini is tender and cheese is melted.
Serve immediately and...ENJOY!