Heat your waffle iron according to the manufacturer’s instructions.
In a large bowl, whisk together the pancake mix, egg, melted butter, milk, and vanilla extract (if using) until smooth.
Allow the batter to sit for 2-3 minutes for better texture.
Lightly coat with non-stick spray to prevent sticking.
Pour batter into the preheated waffle iron, spreading evenly. Close the lid and cook for 3-5 minutes, or until golden brown and crispy.
Remove the waffle carefully and serve warm with butter, syrup, fresh fruit, or your favorite toppings!