Gather all ingredients.

Whisk egg, melted butter, vanilla, and milk together in a separate bowl until smooth.

Whisk egg, melted butter, vanilla, and milk together in a separate bowl until smooth.

Pour milk mixture into flour mixture; stir just until combined. Batter should be slightly lumpy. Let batter rest for 5 minutes to thicken.

Preheat a griddle over medium-low heat. Coat hot griddle with cooking spray just before adding batter.

Pour about ¼ cup batter per pancake onto the preheated griddle. Cook until bubbles form on top and edges look set, 2 to 3 minutes. Flip and cook until golden on the second side, 1 to 2 minutes more. Serve warm.