Preheat your oven to 400°F (200°C) for even cooking.
In a large mixing bowl, combine ground turkey, lightly beaten egg, seasoned breadcrumbs, ¾ cup pesto, parmesan cheese, salt, and pepper. Mix until just combined.
Form the mixture into meatballs about 1 to 1.5 inches in diameter and place on a parchment-lined baking sheet.
Drizzle meatballs with 1 tablespoon olive oil and bake for 20-25 minutes until golden brown and cooked through.
While baking, cut the baguette in half lengthwise and spread remaining ¾ cup pesto on cut sides.
Once meatballs are cooked, place them on the pesto-covered baguette and top with mozzarella and additional parmesan.
Return the baguette to the oven and bake for another 5-7 minutes until the cheese is melted and bubbly.
Let the melts cool for a minute, then garnish with fresh basil leaves before slicing and serving.
