Separate the yolkes & the egg whites and put them in two large bowls. Put the sugar in the same bowl as the egg whites and whisk them until they´re fluffy, white and thick like you´re making meringue (if you have an electric hand mixer use that so it doesn´t take long).
Whisk the yolkes (not with the electric hand mixer) and add the flour. It´s going to crumble but that´s fine. Add the milk, sour milk and whisk until it becomes a smooth batter. Add the salt, vanilla sugar and baking powder. Lastly add the egg whites little by little as you fold it into the batter carefully with a silicone spatula (dough/batter scraper). Make sure the egg whites blends well with the batter.
Put canola oil on a skillet and heat it up to medium, when the skillet is all heated up switch the heat to low. Put batter on the skillet (optional amount). If you have any shapes you can use that as well. I made some heart shapes as well. Don´t forget to dip the shapes in oil just so that the batter doesn´t get stuck. Put a lid on for a few seconds just so the heat makes sure that the top of the pancakes get cooked as well (especially if you´re making them thick). You can turn the heat up to medium and flip the pancake when the underside has a brown looking surface. Repeat the same procedur until they´re all cooked.
If you want to make blueberry pancakes or chocolate chip pancakes put a little batter on the skillet and then put some bluberries or chocolate chips on the top and then a little more batter to cover the chocolate/bluberries.
While you´re cooking the pancakes you can prepare whatever you´re serving the pancakes with but don´t forget to keep and eye on the pancakes so they don´t get burned