Separate egg white and yolks into 2 different bowls. Note: Use room temperature eggs so that egg whites whip up more easily.
In the bowl with egg yolks, add milk, melted butter and vanilla extract. Mix well. Add cake flour (and baking powder if you prefer) and combine evenly until a sticky batter forms.
Note: If done right, the pancakes should be fluffy enough without using baking powder. But you can use baking powder if you want to ensure your pancakes are extra fluffy.
In the bowl with egg whites, add cream of tartar and beat egg whites till foamy. Then add half the sugar and beat egg whites. Finally, add rest of the sugar and beat till stiff peaks form.
Fold half the meringue (beaten egg whites) into the sticky batter gently. Add rest of the meringue and fold gently until well combined.
Note: In order to get a light and airy souffle pancake, it is important to fold the meringue gently to prevent air from escaping.
Heat a frypan over medium-low heat and grease with butter. Grease 3-4 ring moulds with oil or butter and place them into the frypan. Fill each mould with batter until 2/3 full.
Note: Avoid using a ring mould that is too tall otherwise the pancakes will take too long to cook.
Cover the frypan with a lid and cook for 5-7 minutes, until the surface is dry. Remove the lid and flip pancakes over. Cook for another 2-3 minutes until the underside is golden brown. Remove pancakes from pan and allow them to cool before gently pushing them out of the mould. Serve with honey & butter or ice cream.