In a large mixing bowl, whisk together the egg, shredded pepper jack cheese, onion, garlic, cilantro, jalapeño, Worcestershire sauce, salt, smoked paprika, cumin, and black pepper.
Add the ground turkey and gently mix until everything is just combined. Avoid overmixing to keep the burgers tender.
Divide the mixture into 6 equal portions and shape into thick patties. Press a small indentation into the center of each patty to prevent puffing during cooking.
Arrange the patties on a parchment-lined tray, cover, and refrigerate for at least 30 minutes or up to 24 hours.
Preheat a grill to high heat and lightly oil the grates.
Grill the chilled patties for about 5 minutes with the lid closed.
Flip the burgers and continue grilling for another 3–5 minutes, or until the internal temperature reaches 165°F (74°C).
During the last 30 seconds, top each burger with a slice of pepper jack cheese if desired.
Toast the burger buns if preferred.
Assemble the Jalapeño Pepper Jack Turkey Burgers with your favorite toppings and serve immediately.