In a large bowl, whisk together the flour, sugar, baking powder, baking soda, and salt.
In a medium bowl or measuring cup mix together the plant-based milk and lemon juice so that it curdles. Whisk in the melted vegan butter. Pour the milk mixture into the dry mixture and gently fold. Now add the aquafaba and continue to fold. Don't overmix the batter, it should be very lumpy. Let the batter rest for 15 to 30 minutes. Side note: I found this resting time didn't make much of a difference, so skip if you prefer.
When ready to cook pancakes, use a large cast iron skillet or non-stick pan. Melt a dab of vegan butter in the pan and then pour in a heaping ⅓ cup of pancake batter. For extra thick pancakes, do not spread the batter. Cook a few minutes until the bottom is browned and bubbles appear on the top of the pancake. Flip and cook 1 to 2 minutes more on the other side. Repeat with the remaining batter.