In a large mixing bowl, combine the ground turkey, apple cider, whole wheat breadcrumbs, egg, finely diced onion, minced garlic, cinnamon, nutmeg, allspice, and the fresh chopped herbs. Gently mix until just combined, being careful not to overmix, which can lead to tough meatballs. Set aside for a few minutes while you prepare your workspace.

Using a cookie scoop or your hands, take portions of the mixture and form them into meatballs, roughly the size of a golf ball. Place the meatballs on a parchment-lined baking sheet and let them chill in the refrigerator for 15-20 minutes.

Heat a large skillet over medium-high heat and add a drizzle of olive oil. Once the oil is shimmering, add the chilled turkey meatballs to the skillet. Sear for about 4-5 minutes on each side until they are golden brown and reach an internal temperature of 165°F.

In the same skillet, pour in the remaining apple cider, maple syrup, and Dijon mustard. Stir and scrape the browned bits from the bottom of the pan as the mixture comes to a gentle simmer. Allow this glaze to cook for about 3-4 minutes until it thickens and becomes syrupy.

Return the cooked meatballs to the skillet, tossing them gently in the glaze until fully coated. Let them simmer for another 1-2 minutes before serving.