Melt the butter and set aside to cool down a bit. I usually microwave it for about 20 seconds and stir it until completely melted.
Whisk together flour, salt, baking powder and sugar.
Add in egg, milk and vanilla extract to the dry ingredients and whisk until well combined.
Add in melted butter and whisk until combined.
Heat a nonstick pan over medium heat. Pour about ¼ cup for each pancake and cook until you see the bubbles forming on top, flip with a spatula and cook the other side too until both sides are golden brown.