In a mixing bowl, whisk together flour, sugar, and salt.
In another bowl, beat eggs, milk, melted butter, and vanilla (if using).
Gradually pour wet ingredients into dry ingredients, whisking until smooth.
Let batter rest for 20–30 minutes at room temperature.
Heat a nonstick skillet over medium heat; lightly coat with butter.
Pour about ¼ cup (60 mL) of batter into the pan, swirling to coat evenly.
Cook for 45–60 seconds until edges lift and bottom is lightly golden.
Flip gently and cook the other side for 15–20 seconds.
Transfer to a wire rack or plate and repeat with the remaining batter.