Use this sugar cookie recipe to make your dove-shaped cookies. To make the royal icing, sift together powdered sugar and meringue powder into the bowl of a stand mixer, then add 5 tablespoons of water.
Use the paddle and mix on medium for about 7 to 10 minutes or until the icing is thick and smooth. This thicker icing will be used to outline the cookies.
If the icing seems too stiff to pipe, add a few drops of water. Stir after each drop. Royal icing gets thin quickly, so start small. Keep this up until the icing is thick and pipeable.
Put approximately 1/4 of the thick royal icing in a piping bag fitted with a small round tip. Cover the remaining icing in an airtight container, so it doesn't dry out—you'll use this later
Outline the cookies with some of the thick icing. Let it dry completely (about 2 hours) before you go to the next step. Save the rest of this thick icing for later.
Add a few drops of water at a time to the remaining icing stored in the airtight container. Stir after each drop until the icing is thin enough to slowly run off the spoon. Let the icing set for a few minutes to let the air bubbles pop.
Transfer the thinned icing to a piping bag.
Fill in the outlined area of each cookie, and then use the tip to gently push the icing to the edges until evenly covered. Add more icing as needed to fully cover each cookie. Let the cookies set until the surface is dry (about 3 hours).
Using the thick icing again, add the eyes and the wing details.
Tint a small amount of the thick icing green with the gel food coloring and another small amount red. Place each color in its own piping bag. Use a small round tip for precision—I use Ateco #2.
Use the green icing to pipe stems and leaves on the doves. Use the red icing for the berries. Take your time.
Let the cookies dry at room temperature overnight (8 hours) before packaging or stacking. Even if they look dry after a couple of hours, the icing can still be soft underneath. Patience is key!