In a blender, combine the spinach, buttermilk, egg, and oil and blend until smooth (about 30 seconds).
In a medium bowl, whisk together the flour, sugar, baking powder, baking soda, and salt. Whisk the wet ingredients into the dry ingredients until just combined.
Grease a large skillet or griddle and heat over medium heat. For each pancake, pour about 1 tablespoon of the batter onto the griddle, leaving space between each for the batter to spread. Cook for 2 minutes per batch or until browned, turning once.