Now I needed a Royal Icing Recipe. So I found this recipe from this website (http://www.kingarthurflour.com/recipes/royal-icing-recipe) You do need Meringue Powder, which can be found at a speciality cooking store, Hobby Lobby or Michaels. The picture is also a link to the website:
2. Mix on low speed at first, increasing to high speed over several minutes. Beat until the icing is fluffy.
3. Keep the frosting covered with a damp towel and some plastic wrap until you have time to use it.
4. Divide the frosting into smaller containers and mix with food coloring for several colors.
5. To use for piping, put a tip in the bottom of a disposable pastry bag. Using a coupler will allow you to change tips with ease.
6. Use a tall, heavy-bottomed glass to hold the pastry bag while you add the frosting. Take care not to fill the bag more than half full.
7. Close the back of the pastry bag with a twist tie or spring clip, to keep the icing from backing up over your hand when you squeeze it.
This is the beautiful Gingerbread house they made: