How to Make It
Beat all ingredients with a stand mixer fitted with a paddle attachment on medium speed until blended, smooth, and stiff, 1 minute (mixture should hold stiff peaks), stopping to scrape down sides as needed. Gradually add additional water 1/2 teaspoon at a time until desired consistency is reached. Spoon mixture into a piping bag fitted with desired tip; pipe onto cookies. Store in an airtight container up to 1 week.