1. In a bowl, whisk egg yolks, milk, vanilla extract, and vegetable oil until well combined.
2. Sift in flour and baking powder, and mix until smooth.
3. In another bowl, beat egg whites until frothy, then gradually add sugar and continue to beat until stiff peaks form.
4. Gently fold the egg whites into the yolk mixture in three parts, being careful not to deflate the batter.
5. Heat a non-stick skillet over low heat and lightly grease it. Scoop the batter onto the skillet, cover with a lid, and cook for about 4-5 minutes on each side until golden brown and cooked through.