In a bowl, combine the egg whites, sugar, cream of tartar, and salt. Whip until stiff peaks form.
In a separate bowl, whisk together the egg yolks, milk, and melted butter until smooth.
Stir in the flour and baking powder until combined. Fold in the egg whites until just combined.
Heat a skillet or griddle over medium heat and lightly oil. Drop the batter in 1/4 cup (60 ml) amounts onto the skillet. Cook until golden brown, about 3-4 minutes.
Flip the pancakes and cook for an additional 3-4 minutes. Serve warm with your favorite toppings.
Interesting Facts
The key to making light and fluffy souffle pancakes is to not over-mix the batter.
Souffle pancakes originated in Japan, where they are also known as "fluffy pancakes".
These pancakes are a popular breakfast food in Japan and are often served with fruit or ice cream.