Preheat your oven to 375°F (190°C).
Prepare the zucchinis by slicing them in half lengthwise and scooping out the seeds.
In a skillet over medium heat, cook the ground chicken until browned and fully cooked.
Add marinara sauce, garlic, Italian seasoning, salt, and pepper to the cooked chicken, stirring to combine.
Remove the skillet from the heat and mix in half of the mozzarella and Parmesan cheeses.
Spoon the chicken mixture into the zucchini halves, packing it generously.
Top the filled zucchinis with the remaining mozzarella and Parmesan cheeses.
Arrange the stuffed zucchinis on a baking sheet and bake for 25–30 minutes.
Let the zucchini boats cool for a few minutes before serving, garnished with fresh basil if desired.
