Grate lemon zest directly into the sugar and rub it in with your fingertips.
Combine flour, baking powder, baking soda, salt, and lemon sugar in a medium bowl and whisk until homogenous.
In a medium clean bowl, whisk the cold egg whites with a pinch of salt until stiff peaks form. In another bowl, whisk yolks, buttermilk, and vanilla until homogenous. Slowly drizzle in the melted butter while whisking. Carefully fold in the stiff egg whites with a rubber spatula until just combined. Pour the mixture over the dry mix and fold until just combined. It's ok if there are still flour lumps.
Heat a large heavy-bottomed nonstick skillet over medium heat for 5 minutes . Add a small amount of coconut oil to the skillet and spread a bit. I do that with a paper towel. Using a 1⁄4-cup as a "spoon" place 4 pancakes in the skillet and cook until bubbles start to appear on top and the bottoms are golden brown, which takes about 2 to 3 minutes. Now, flip the pancakes and cook on the second side until golden brown and completely set, about 2 minutes longer.
Serve the pancakes immediately, or keep warm on a wire rack set on a rimmed baking sheet in a warm oven while you cook the remaining batches. Serve with blueberry syrup.
Place berries in a pot with the salt, maple syrup and lemon juice and let come to a boil. Reduce the temperature and let simmer for 15 minutes.