In a large bowl, whisk together the flour, sugar, baking powder, baking soda, salt, lemon zest and chia seeds. Set aside.
In a medium bowl, whisk together the buttermilk, egg yolks, and melted butter. Using a hand mixer or stand mixer fitted with a whisk attachment, whisk the egg whites over low speed until foamy. Increase speed to medium-high and whisk until egg whites are stiff (peaks will hold) but still wet. Set aside.
Add the buttermilk mixture to the dry ingredients, and whisk until just combined. Using a spatula, gently fold the egg whites, in two separate additions.
Heat a tab of butter in large non-stick or cast iron skillet over medium heat. Once the butter begins to sizzle, gently add the batter to the pan (you can always a test coin-sized pancake to check whether the pan is ready).
Once bubbles begin to form on the top of the pancake, flip carefully and continue to cook on other side until brown–this step is easier if you keep pancakes no larger than 4 to 5 inches in diameter. Adjust heat if necessary. Top pancakes with butter and warm maple syrup, and serve immediately.
Tips for Success:
If you would prefer a slightly more indulgent option, feel free to use a 50/50 blend of flour: 50% whole wheat pastry flour (120 grams) and 50% all-purpose (120 grams)!