In a large bowl, sift together the flour, baking powder, salt, and sugar.
Make a well in the middle and pour in the milk, egg, butter, and vanilla. Use a fork to break up the egg in the middle of the bowl and then slowly mix it with the milk and other ingredients, always mixing from the outside of the bowl in until all clumps are gone.
Add the food coloring and with a spatula, gently fold in the batter until it reaches the desired shade of green. For a darker green, add additional food coloring.
Cook:
Heat a non-stick griddle or large pan over medium-high heat. Once hot, grease it and immediately pour ¼ cup of batter for each pancake.
Cook for 2 minutes and wait until bubbles form to flip. Continue cooking for an additional minute or two to cook through. Remove from the pan or griddle and keep warm while you cook the rest of the batter.
To make the glaze:
In a medium bowl, mix the powdered sugar with milk until smooth. Pour over the pancakes.
Notes
Use the right baking powder: Since pancake batter naturally has a mild, neutral flavor, it's important to use aluminum-free baking powder. The metallic flavor will ruin the taste, especially in fluffy pancake recipes that call for 2 or more teaspoons. Trust me on this one.