Place the minced turkey, onion, garlic, egg, bread crumbs, Parmigiano-Reggiano cheese, parsley, pesto, milk, salt and black pepper in a bowl. Mix until evenly blended, then form into balls. Make a hole in the rissole with your finger and place a cheese cube in the hole. Seal the ball around the cheese and place on a nonstick baking tray. Drizzle the olive oil over the rissoles.
Bake in the preheated oven until the rissoles are no longer pink in the centre, about 30 minutes. If serving on spaghetti, heat the pasta sauce in a saucepan over low heat. Bring to a simmer, and place the baked rissoles in the pasta sauce for about 2 minutes.