Preheat the oven to 350 degrees F. Mix coconut flakes and 1/2 teaspoon of the granulated sugar. Place the mixture on a sheet pan and bake for about 3-5 minutes, stirring half way through. Be careful not to burn the coconut. Once finished, transfer to a blender or food procesor and pulse until fine.
In a large bowl, add the flour, coconut mixture, baking powder, baking soda, salt, and sugar. Whisk to combine and set aside. In a separate bowl, mix the cooled butter, vanilla, lemon juice, lemon zest, buttermilk, and egg yolks. Beat the egg whites to stiff peaks in the bowl of a stand mixer or using an electric mixer; set aside.
Combine the wet and dry ingredients by gently folding the liquids into the dry mixture until just combined. Add half of the beaten egg whites to the batter, gently stir with a rubber spatula, then add the other half. Gently fold until just combined.
Bring your griddle or pan to medium heat and spritz lightly with non stick spray. Let heat for about 5 minutes before pouring in about a 1/4 cup of the pancake batter. Flip the pancakes when the edges are golden and bubbles appear on the surface unpopped; cook the other side for about 2 minutes. Repeat with remaining pancake batter.