Preheat the oven to 425°F (220°C). Line a rimmed baking sheet with parchment paper and lightly brush or spray with olive oil.

Mix the panade: In a large bowl, stir together breadcrumbs and milk. Let it sit 2–3 minutes until the breadcrumbs absorb the liquid. This keeps the meatballs tender.

Add aromatics and seasonings: Mix in grated onion, garlic, Parmesan, parsley (or Italian seasoning), salt, pepper, and any optional spices. Stir until evenly combined.

Add the turkey and egg: Add ground turkey and the egg to the bowl. Use a fork or your hands to gently mix until just combined. Do not overmix, or the meatballs can turn dense.

Shape the meatballs: Lightly oil your hands. Roll the mixture into 1½-inch balls (about 2 tablespoons each). You should get 18–22 meatballs, depending on size.

Arrange and oil: Place meatballs on the prepared sheet with a little space between each. Lightly brush or mist the tops with olive oil for better browning.

Bake: Bake for 12–15 minutes, until the centers are cooked through and the internal temperature hits 165°F (74°C).

Optional broil: For extra browning, broil for 1–2 minutes at the end. Watch closely to prevent burning.

Rest and serve: Let the meatballs rest 3–5 minutes. Serve with marinara over pasta, tuck into a sub with melted provolone, or pair with rice and veggies.