(This will cover 2-3 dozen 3.5 inch cookies in 2 colors; I usually double this recipe.)
4 TBSP meringue powder
scant ½ cup water
1 lb powdered sugar
½-1 tsp light corn syrup
few drops clear extract (optional)
Combine the meringue powder and water. With the paddle attachment of an electric mixer, beat until combined and foamy. Sift in the powdered sugar and beat on low to combine. (Do NOT skip the sifting!)
Add in the corn syrup and extract if desired. ( I think the corn syrup helps keep the icing shiny.)
Increase speed to med-high/high and beat for about 5 minutes, just until the icing is glossy and stiff peaks form.
You should be able to remove the beater from the mixer and hold up and jiggle without the peak falling.
Do not over beat.
Cover with plastic wrap touching the icing or divide and color using gel paste food colorings.
This "stiff" icing is perfect for outlining and even for building gingerbread houses and monogramming. Use a #2 tip to pipe this part.
To fill in your cookies, add water to your icing a teaspoon at a time, stirring with a rubber spatula, until it is the consistency of syrup. This technique of filling a cookie with thinned icing is called "flooding."
Bridget's site with recipe: http://bakeat350.blogspot.com/2010/01/royal-icing-102-or-201-or-whatever.html
Bridget's friend's site with more icing tips: http://bloomingonbainbridge.blogspot.com/2011/12/bridgets-pink-and-red-christmas.html
Pioneer Woman cookie decorating class: http://thepioneerwoman.com/cooking/2010/12/decorated-christmas-cookies/
I never knew there was a difference in Meringue. We have the Wilton brand but I would definitely be interested in having a taste test.