In a large mixing bowl, sift together flour, baking powder, salt and sugar. Make a well in the center.
Measure the milk into a measuring cup. Add vinegar and ground flax seeds, and use a fork to vigorously mix the ingredients until foamy. This will take a minute or so.
Pour the milk mixture into the center of the dry ingredients. Add the water, canola oil and vanilla and use a fork to mix until a thick, lumpy batter forms. That should take about a minute. It doesn’t need to be smooth, just make sure you get all the ingredients incorporated.
Preheat the pan over medium-low heat and let the batter rest for 10 minutes.
Lightly coat the pan in oil. Add 1/3 cup of batter for each pancake, and cook for about 4 minutes, until puffy. Flip the pancakes, adding a new coat of oil to the pan, and cook for another 3 minutes or so. Pancake should be about an inch thick, and golden brown.
Rest pancakes on a cooling rack covered with tin foil until ready to serve. To reheat, place pancakes in on a baking sheet covered with tin foil in a 300 F degree oven for 5 minutes or so.
http://www.theppk.com/2011/12/puffy-pillow-pancakes/