In a large bowl, whisk together the egg yolks, sugar, milk, vanilla and pancake mix. Blend until smooth with no visible large lumps.
In a separate bowl, beat the egg whites with an electric mixer on medium-high speed until stiff peaks form (about 2-3 minutes).
Carefully, fold about ⅓ of the egg whites into the pancake batter mixture until just incorporated. Add the remaining egg whites and fold them into the pancake batter until just incorporated. The egg whites should be folded in gently so you don't deflate the batter.
Generously grease the inside of 2 ring molds. Coat a large nonstick skillet with cooking spray (or unsalted butter) and heat over low heat. Put the prepared ring molds in the middle of the skillet.
Fill the molds with the batter (about ¾ of the way full). Cover the skillet and cook for about 10 minutes or until the center of the pancakes are almost completely set. They will still have a slight jiggly center.
Release the bottom of the pancakes with a spatula. With the help of kitchen tongs, grasp the sides of the ring molds and carefully flip them over making sure you don’t spill any batter.
Cover and cook for about 5-7 minutes or until the pancakes are set and golden brown.
Transfer to a plate and remove the molds. Serve immediately with your preferred toppings. The pancakes should be eaten before they deflate.