I love this icing because it’s foolproof, versatile, and dries to a beautiful finish. Whether I’m outlining shapes, flooding cookies with vibrant colors, or adding fine decorative details, it holds its shape and sets up quickly. The meringue powder gives it that classic royal icing texture—smooth when applied, but firm once dry. Plus, it’s easy to make ahead and keeps well in an airtight container.
Ingredients
(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)
2 cups powdered sugar
2 tablespoons meringue powder
¼ cup water
1 teaspoon vanilla extract
Food coloring (optional)
Directions
I start by adding the powdered sugar and meringue powder to a mixing bowl.
I add the water and vanilla extract.
Using a hand mixer or stand mixer, I beat the mixture on low until combined, then on medium-high for 1–2 minutes until it becomes smooth and glossy.
I check the consistency—if it’s too thick, I add water a few drops at a time; if too thin, I mix in a bit more powdered sugar.
If I want different colors, I divide the icing into separate bowls and stir in gel or liquid food coloring.
For outlining, I keep the icing thick (like toothpaste).
For flooding, I thin the icing slightly so it spreads smoothly but doesn’t run over the edges.
I transfer the icing into piping bags or squeeze bottles, depending on the design.
I decorate cookies as desired and let them sit at room temperature until fully dry—usually 6–12 hours depending on humidity.
I store any unused icing in an airtight container in the fridge for up to 1 week, stirring before using again.
Servings and timing
This recipe makes about 2 cups of icing, enough to decorate approximately 24–36 cookies depending on size. Prep time: 10 minutes Cook time: 0 minutes Total time: 10 minutes
Variations
Sometimes I swap vanilla extract for almond or lemon extract for a different flavor. For a shimmer effect, I mix in edible luster dust or brush it on after the icing dries. When I want a matte finish, I skip the gloss by using less water and letting the icing air dry completely.
Storage/Reheating
I store leftover icing in an airtight container in the refrigerator for up to a week. When I’m ready to use it again, I stir well to bring back the smooth consistency. If it thickens too much, I add a few drops of water to loosen it.
FAQs
How long does this icing take to harden?
The icing starts to crust within 30 minutes and fully hardens in 6–12 hours depending on humidity and thickness.
Can I use this icing on other baked goods?
Yes, I’ve used it on gingerbread cookies and even to decorate cakes and cupcakes. It holds shape well and dries firm.
What’s the difference between this and glaze icing?
This icing contains meringue powder, which helps it harden and hold detail. Glaze icing, usually made with just powdered sugar and milk or water, stays softer and shinier but doesn’t dry as firm.
Can I freeze cookies decorated with this icing?
Yes, once the icing is completely dry, I freeze decorated cookies between layers of parchment in an airtight container. I let them thaw uncovered to avoid condensation on the icing.
What if I don’t have meringue powder?
Unfortunately, this recipe relies on meringue powder to achieve the right texture and finish. If I don’t have any, I make a glaze-style icing instead using just powdered sugar and milk, but it won’t harden the same way.
Conclusion
This Sugar Cookie Icing That Hardens is my go-to for beautifully decorated cookies that look and taste amazing. It’s easy to mix, dries glossy and firm, and gives me the control I need whether I’m outlining, flooding, or getting creative with details. If I’m decorating cookies for holidays, birthdays, or gifting, this icing never lets me down.
This sugar cookie icing hardens to a smooth, glossy finish—perfect for decorating cookies with vibrant color and clean lines. Easy to make in just 10 minutes!
Author:Sarah
Prep Time:10 minutes
Cook Time:0 minutes
Total Time:10 minutes
Yield:About 2 cups (enough for 24–36 cookies, depending on size)
Category:Dessert
Method:Mixing
Cuisine:American
Diet:Vegetarian
Ingredients
2 cups powdered sugar
2 tablespoons meringue powder
¼ cup water
1 teaspoon vanilla extract
Food coloring (optional)
Instructions
In a mixing bowl, combine powdered sugar and meringue powder.
Add water and vanilla extract.
Mix until smooth, glossy, and well blended.
If desired, divide icing into separate bowls and stir in food coloring.
Use immediately to decorate cookies or store in an airtight container.
For outlining cookies, use a thicker consistency.
For flooding cookies, thin the icing with a few drops of water at a time.
Transfer icing to piping bags or squeeze bottles for easy decorating.
Let cookies sit uncovered at room temperature for several hours to harden.
Enjoy your beautifully decorated, firm-to-the-touch cookies!
Notes
For best results, allow decorated cookies to dry completely (about 6–12 hours).
Store leftover icing in an airtight container in the fridge for up to 1 week.
Stir well before reusing and adjust thickness with water or powdered sugar.
