Add the lemon juice to a liquid measuring cup and then add enough milk to match the amount of milk listed. Stir and let sit 5 minutes to emulate buttermilk.
In a large bowl, add the flour, sugar, salt, baking powder, and baking soda. Add cinnamon or cinnamon chips or poppy seeds (6 tablespoons) as desired. Whisk to combine.
To the milk and lemon juice mixture, add the melted butter, and egg yolks, whisk to combine.
Add the milk mixture to the dry ingredients and gently fold with a rubber spatula until just combined. Add the egg whites and fold until just combined. Be sure not to overmix. Some lumps are okay.
Let the batter rest for 15-30 minutes at room temperature.
Heat a pan over medium low heat. Butter the pan and add ⅓ cup or 75 grams of batter to the pan.
Cook for 2-3 minutes, until bubbles start to appear on the surface. If adding any toppings like chocolate chips or blueberries, sprinkle over the pancake. Flip the pancake over and cook for another 1-2 minutes, until golden brown. Repeat with the remaining batter.
