Have your sugar cookies baked and cooled. You can use this recipe, or your favorite recipe for sugar cookies. This icing is enough to ice 2 dozen cookies.

Pour sifted confectioners’ sugar, meringue powder, and 9 Tablespoons of water into a large bowl. Using a hand mixer or a stand mixer fitted with a whisk attachment, beat icing ingredients together on high speed for 1.5–2 minutes. When lifting the whisk up off the icing, the icing should drizzle down and smooth out within 5–10 seconds. If it’s too thick, beat in more water 1 Tablespoon at a time. I usually need 10 Tablespoons, but on particularly dry days, I use up to 12–14 Tablespoons. Keep in mind that the longer you beat the royal icing, the thicker it becomes. If your royal icing is too thin, just keep beating it to introduce more air, OR you can add more sifted confectioners’ sugar. See this video if you need a visual.

Color the Icing: If you’d like to tint the icing, divide it into separate bowls for each color, or tint the entire batch one color. A little gel food coloring goes a long way, so use a toothpick to dot the gel into the icing. Stir it in, and then add more to deepen the color if desired. Keep in mind that the more you stir, the thicker the icing becomes. If needed, stir in a few drops of water to maintain the target consistency.

Fill the Pastry Bag: Fit a pastry bag with a small round piping tip (and use a coupler if you plan to switch icing colors and/or piping tips), such as Wilton piping tip #4. Fill the bag with icing, making sure to leave a few inches of space at the top of the bag. Twist to seal or use a clip.

using any of the following methods, then continue to step 10.

Using a small round piping tip such as Wilton piping tip #4, pipe an outline of icing all around your cookie. Then fill in the center of the outline with more icing. If desired, you can add some sprinkles while the icing is still wet.

Start by piping and flooding the cookie with a layer of icing, just as described above. Let that set for 1–2 hours, and then pipe on a second layer of icing details once the first layer has dried, such as swirls, handwriting, dots, and other designs. A smaller piping tip, such as Wilton piping tip #2, is ideal for intricate designs/details. Let the icing set again before you stack and store the cookies.

This look gives the icing decoration some dimension. Also, if you’re using multiple colors, this method keeps the colors from bleeding together. Start with one color, and using Wilton piping tip #4, pipe every other section or area of your cookie, then let it set before you pipe the remaining sections/areas. For the pictured pumpkin and tree cookies, I outline and flood the center, and then the two sides, leaving space between each section. Let the icing dry for at least 30 minutes, until the icing has begun to set. Once the icing is semi-set, you can go ahead and fill the remaining sections with icing.

This technique gives the cookie that same sectioned look as #3, but you don’t have to wait 30 minutes for the first section to set. Using Wilton piping tip #4, start by piping on the section you want to cover with sprinkles or sparkling sugar. Dip the cookie into the sprinkles, so that they completely coat the icing. Then pipe on your remaining sections.

When applied to cookies in a thin layer, royal icing completely dries in about 2 hours at room temperature. If icing consistency is too thin and runny, it will take longer to dry. If the icing is applied very thick on cookies, it will also take longer to dry. If you’re layering royal icing onto cookies for specific designs and need it to set quickly, place cookies in the refrigerator to help speed it up.