Preheat the oven to 400°F (200°C) and lightly spray a baking sheet with cooking spray.
In a small food processor or chopper, combine the jalapeño (seeded as desired), garlic, cilantro, and scallions and pulse until finely minced.
In a large bowl, add the ground turkey, the minced jalapeño mixture, bread crumbs, egg, cumin, oregano, and a pinch of salt and pepper.
Mix by hand until just combined; avoid overworking the meat.
Scoop 1/4 cup of the mixture, divide it in half to make two portions (each about 1/8 cup), roll into meatballs, and place them on the prepared baking sheet. Repeat to make about 24 meatballs.
Bake the meatballs in the preheated oven for 15 minutes, or until cooked through and internal temperature reaches 165°F (74°C).
Remove from oven and serve warm with the Creamy Cilantro Tomatillo Dipping Sauce, if using.