In a large mixing bowl, combine the powdered sugar and meringue powder.
Add water gradually, mixing until smooth.
Incorporate vanilla extract for flavor.
Mix until the icing reaches a glossy texture.
Divide icing into smaller bowls for coloring if desired.
Add food coloring to each bowl, mixing well.
To achieve a thicker consistency, add more powdered sugar.
For a thinner icing, add more water as needed.
Transfer icing to piping bags or squeeze bottles for easy application.
Decorate cookies as desired and allow icing to set.