Sift flour, baking powder, sugar, and salt into a medium bowl

Whisk in the milk, melted butter, beaten egg, and vanilla extract to the flour mixture until combined and smooth. Let rest 5 minutes

While batter is resting, heat a griddle over medium heat. When hot, spray with cooking spray and add about 1/4 cup of batter per pancake. Cook on one side until bubbles form

Flip over and cook for about 1 minute on the other side. Serve immediately