1. In a large bowl whisk together the egg yolks, sour cream, milk, sugar, salt, vanilla, and baking powder.
2. In a separate large bowl add flour and blueberries and toss to combine, making sure berries are fully coated in the flour.
3. Add flour mixture to the wet milk mixture, and stir just to combine; do not over mix! The batter will be thick, so don't worry if there's a lot of clumps left.
4. Add egg whites to a large bowl or the body of a stand mixer. Beat using a handheld mixer or the whisk attachment until the whites begin to form soft peaks.
5. With a rubber spatula fold egg whites into flour/sour cream mixture, stirring until fully incorporated.
6. Melt 1 tablespoon of butter in a large skillet over medium heat.
7. Ladle 1/3 cup scoops of the batter into the skillet, only cooking a few at a time so they don't blend together.
8. Cook pancakes until the edges begin to brown and the top of the batter bubbles, then flip and cook for another 1-2 minutes. Repeat for all pancake batter.
9. Top pancakes with syrup and extra blueberries, or anything else your heart desires! Serve at once.