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. I start with 3, then add one more (sometimes you can squeeze too much).
Cook:
Heat a non-stick griddle or large pan over medium heat. Once hot, grease it and immediately pour ¼ cup of batter for each pancake. Cook for about 2 minutes and wait until bubbles form to flip. Continue cooking for an additional minute or two until they're done. Remove them from the pan or griddle and keep warm while you cook the rest. If your first side is cooking fast (burning) and you flip them over before you see bubbles, cool the pan, and lower the heat.
To make the glaze:
In a medium bowl, mix the powdered sugar with milk until smooth. Pour over the pancakes.
Notes
Aluminum is added to many brands of baking powder, and it often leaves a metallic or salty aftertaste in pancake batter.