Preheat the oven to 400°F.
Lightly grease a metal baking sheet with oil.
In a large bowl, combine the breadcrumbs and milk. Let sit for 2 minutes until softened.
Add the mayonnaise, Worcestershire sauce, pesto, egg, garlic, grated onion, Italian seasoning, salt, pepper, parsley, and olive oil. Stir until smooth.
Add the ground turkey, mozzarella cheese, and parmesan cheese.
Gently mix until just combined. Do not overmix.
Let the mixture rest for 5 minutes so the breadcrumbs fully hydrate.
Lightly shape into 20 meatballs, about 1 ½ tablespoons each.
Arrange the meatballs on the prepared baking sheet with space between each one.
Bake for 16 to 18 minutes, or until the centers reach 160°F.
Optional: Broil for 30 seconds for additional browning.
Rest for 2 to 3 minutes before serving. Carryover cooking will bring the meatballs to 165°F.
Serve with marinara sauce, fresh basil, and parmesan cheese.