01 - Combine milk, spinach, eggs, melted butter, and vanilla extract in a blender. Blend until completely smooth and vibrant green.
02 - Whisk together flour, sugar, baking powder, baking soda, and salt in a large bowl until well incorporated.
03 - Pour the spinach mixture into the dry ingredients. Stir gently until just combined; do not overmix as a few lumps are acceptable.
04 - Heat a non-stick skillet or griddle over medium heat. Lightly grease with butter or cooking oil.
05 - Pour 1/4 cup of batter per pancake onto the skillet. Cook for 2-3 minutes until bubbles form on surface and edges appear set. Flip and cook for another 1-2 minutes until golden and cooked through.
06 - Repeat with remaining batter, greasing the skillet as needed between batches.
07 - Serve pancakes warm with maple syrup and additional butter if desired.