Preheat your Blackstone griddle over medium-high heat.
In a large skillet, cook the ground beef over medium heat until browned and cooked through, breaking it apart with a spatula as it cooks.
Add the diced onion and minced garlic to the skillet with the cooked ground beef. Cook for an additional 2-3 minutes until the onion is softened.
Stir in the Worcestershire sauce, salt, and pepper, then remove the skillet from the heat.
Place one tortilla on the preheated Blackstone griddle and sprinkle half of the shredded cheddar cheese evenly over the tortilla.
Spoon half of the cooked ground beef mixture on top of the cheese-covered tortilla, spreading it out evenly.
Sprinkle additional shredded cheese over the ground beef mixture, then top with another tortilla.
Cook the quesadilla for 2-3 minutes on each side, or until the tortillas are crispy and the cheese is melted and gooey.
Repeat the process with the remaining tortillas and filling ingredients to make the second quesadilla.
Once both quesadillas are cooked, remove them from the griddle and let them cool for a minute before slicing into wedges.
Serve the Blackstone Cheeseburger Quesadillas hot, garnished with optional toppings as desired.
