Preheat your oven to 375°F (190°C).
Prepare the zucchinis by slicing them in half lengthwise and scooping out the center.
In a skillet, heat the olive oil over medium heat. Add the ground chicken and cook until fully browned, breaking it apart as it cooks.
Stir in the marinara sauce, Italian seasoning, salt, and pepper. Cook for an additional 2-3 minutes until heated through.
Remove the skillet from the heat and mix in half of the mozzarella and all of the Parmesan cheese.
Spoon the chicken mixture evenly into each zucchini half.
Top each stuffed zucchini with the remaining mozzarella cheese.
Place the filled zucchinis on a baking sheet and bake for 25-30 minutes.
Remove from the oven and let cool for a few minutes before serving.
