Whisk the eggs in a large bowl.
Add the milk, sugar, salt, and vanilla.
Add the flour gradually.
Whisk just until the batter is smooth.
Let the batter rest for 10 to 15 minutes.
Heat a 10 inch nonstick or well seasoned skillet over medium heat.
Add about 1 teaspoon butter and swirl to coat the pan.
Pour in roughly 1/3 cup batter.
Tilt the pan quickly.
Spread the batter into a thin, even circle.
Cook for 1 to 2 minutes, until the top looks mostly set.
Flip carefully with a thin spatula.
Cook the second side for 30 to 60 seconds.
Slide the pancake onto a plate.
Repeat with the remaining batter.
If you’re adding bacon or apple slices, place them in the butter first.
Pour the batter over them.