01 - Combine milk, fresh spinach, eggs, melted butter, and vanilla extract in a blender. Blend on high speed until completely smooth and vibrant green, with no visible spinach pieces.
02 - Whisk together flour, sugar, baking powder, baking soda, and salt in a large mixing bowl until evenly distributed.
03 - Pour the green spinach mixture into the dry ingredients. Stir gently with a spatula or whisk just until combined; the batter should remain slightly lumpy. Avoid overmixing to prevent tough pancakes.
04 - Place a non-stick skillet or griddle over medium heat. Lightly grease the surface with butter or cooking oil.
05 - Pour approximately 1/4 cup of batter per pancake onto the heated skillet. Cook for 2 to 3 minutes until bubbles form across the surface and edges appear set. Flip carefully and cook for an additional 1 to 2 minutes until golden brown and cooked through.
06 - Continue with remaining batter, lightly greasing the skillet between batches as needed. Stack cooked pancakes on a plate.
07 - Serve pancakes immediately while warm, topped with maple syrup and additional butter if desired.