Melt the butter in microwave for 30 seconds, set aside.
In a medium bowl, mix together flour, sugar, salt, and baking powder.
Stir milk and egg together.
Create a well in the center of the flour mixture.
Pour the butter, vanilla, and milk mixture into the well.
Use a wire whisk to stir everything together until just combined. It will be slightly thick and lumpy, but should be well incorporated.
Allow the batter to rest while heating a lightly oiled skillet or griddle to medium high heat.
Pour or scoop the batter onto the griddle, using approximately 1/4 cup for each pancake.
Cook each side for 3-6 minutes, until lightly golden brown.
Make sure you are using BAKING POWDER, not baking soda.I like to set my electric griddle to 325 degrees and spray with nonstick spray. I use a 1/4 measuring cup to scoop the pancake batter onto the griddle. The pancake batter will be thick.Check the text of the post above or read through the comments for common substitutions (such as nut milks, omitting the butter, using alternative flours, etc). I haven't personally tried these, but many others have had great success.I don't recommend making these pancakes in advance, but you can freeze any leftovers.