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This Christmas cookie icing recipe that hardens is the secret weapon for beautifully decorated holiday cookies. It dries glossy, firm, and smooth, perfect for outlining, flooding, details, gingerbread houses, and any Christmas cutouts. And the best part? No raw egg whites. Just a few pantry ingredients and foolproof results.
Since you’re here for icing that actually sets, you’ll love my Cutout Sugar Cookies That Don’t Spread, my Christmas Marbled Sugar Cookies, Gingerbread Men Cookies, and this ultra-popular Christmas Fudge.
I made our traditional sugar cookies tonight and with this frosting recipe they turned out so much better! I love this recipe and the sheen of the hardened frosting on my sugar cookies. This had to be the easiest frosting recipe I’ve used and had a great taste too! Thank you for sharing. I will save it and use it again!
Let’s Chit Chat!
I actually fell in love with this style of icing years ago at a hotel, they handed me a little welcome cookie, and the first thing I noticed was that the icing didn’t smear. I stacked it in a napkin, tossed it in my bag, eventually ate it… and it still held that glossy, picture-perfect finish.
From that moment I thought, okay, I need to recreate this at home, not just for myself, but so anyone can make sugar cookies that look bakery-quality without stressing about runny icing or raw egg whites.
After a lot of testing (and way too many cookies), this is the recipe that captures that same magical finish: smooth, shiny, and totally smudge-proof once it hardens.
Why This Is the Best Cookie Icing Recipe That Hardens
- Uses simple ingredients you already have at home
- Dries with a gorgeous glossy finish thanks to corn syrup
- Perfect consistency for outlining, flooding, or writing
- Beginner-friendly – no meringue powder, no egg whites, no stress
- Ideal for Christmas cookies, gingerbread houses, and every holiday decorating project
Ingredients You’ll Need
(Scroll to the recipe card for full measurements.)
- Powdered sugar (aka confectioners’ sugar)
- Corn syrup – gives the icing shine and structure
- Clear vanilla extract – for bright white icing
- Milk or water – adjust to reach your desired consistency
- Gel food coloring – vibrant color without thinning the icing
How to Make Sugar Cookie Icing That Hardens
- Mix the base: In a large bowl, whisk together powdered sugar, vanilla, milk, and corn syrup.
- Adjust consistency: Add tiny drops of milk to thin, or extra powdered sugar to thicken. For flooding, aim for it to be slightly runny. For outlines/details, aim for a thicker texture.
- Color the icing: Divide into bowls and tint each with gel food coloring.
- Decorate: Use squeeze bottles or piping bags with small tips. Let decorated cookies dry completely before stacking or packaging.
Recipe Tip For This Cookie Icing That Hardens
- Use powdered sugar made with tapioca starch instead of cornstarch, it blends smoother and eliminates that chalky aftertaste some icings get.
- Add liquid slowly. A few drops can take your icing from outline-thick to flooding-thin, so adjust in tiny increments.
- Stick to gel food coloring to avoid thinning the icing.
- Cover your bowls with a damp towel so the icing doesn’t crust while you work.
- Let cookies dry completely (6–24 hours depending on thickness) before stacking or packaging for crisp, smudge-free designs.
Frequently asked questions – FAQ
Store in a squeeze bottle or airtight container in the fridge for up to 3 days. Bring to room temperature before using.
Yes, but your icing won’t be bright white. It’s perfect if you plan to add food coloring anyway.
You can, but reduce the milk slightly since it adds extra liquid.
Add more powdered sugar until it thickens.
Try clear vanilla extract, almond extract, coconut extract, or lemon extract so the icing stays white.
Anywhere from 6–24 hours, depending on thickness and humidity.
Store fully dried cookies in an airtight container for up to 2 weeks. Separate layers with parchment to protect the designs.
Sugar cookie icing that hardens
Ingredients
- 2 cup powdered sugar
- 1 & 1/2 tbsp corn syrup
- 1/2 tsp vanilla extract
- 1 & 1/2 tbsp milk or water cold
- gel food coloring
Instructions
- Sift the powdered sugar in a medium/large bowl. Add in the corn syrup, vanilla extract, and milk or water. Stir vigorously until smooth.2 cup powdered sugar, 1 & 1/2 tbsp corn syrup, 1/2 tsp vanilla extract, 1 & 1/2 tbsp milk or water
- Add more milk is needed to get to your desired consistency. You want the icing to slowly fall off the spoon, leaving a pretty thick layer behind it.
- Divide the icing into multiple smaller bowls if making multiple different colored batches. Use to decorate cookies, let the icing set at room temperature before storing the cookies in an air tight container.gel food coloring
Nutrition information is automatically calculated, so should only be used as an approximation.
it calls for gel coloring, can I use powdered coloring?
Yes! Adjust how much you add to get your preferred color!
How do I know which brands of powdered sugar use tapioca starch?
Hi Teri! It should say it in the ingredient list in the back of the package. I found that Wholesome sugar and the Trader Joe’s brand don’t have cornstarch in them.
How does the icing hold up once the cookie has been frozen?
It freezes great! Since it’s mostly sugar and corn syrup, it doesn’t get icy or crack. Just freeze after it sets and thaw the cookies covered so moisture doesn’t mess with the finish 😊
Will any decorating piping kit work for the application of the icing?
I believe so, yes!
I cannot wait to try this icing!!!
Can you share the sugar cookie recipe as well? I currently do not have one.
I have a cutout sugar cookie recipe I am updating, except it by the end of the week!
Can you tell me how many cookies this will cover?
that’s a little difficult because that depends on the size of your cookies. Sugar cookies could be small, medium, large, or cut into intricate shapes. I don’t want to give you a wrong answer.
Hi there, is there a corn syrup substitute for those in the UK?
From my research, I’ve found that people in the UK use something called Golden Syrup or Glucose Syrup.
Can you substitute the Vanilla Extract for a different flavor, say something like Peppermint?
Absolutely!
can I add cocoa powder?
Yes you can, up to 3 tablespoons. Just know that you might have to add a tablespoon more of milk just to even out the texture.
I normally use a buttercream frosting on my sugar cookies, but I wanted a frosting that would mail easier to my grandkids. Most importantly, does your icing taste good? 😊
That’s so sweet that you’re mailing cookies to your grandkids! ❤️ This icing is perfect for that because it hardens beautifully, making it great for shipping. For the best flavor, I recommend using high-quality vanilla and powdered sugar without cornstarch. Trader Joe’s powdered sugar with tapioca starch is a great option! Hope they love the cookies! 😊
I made our traditional sugar cookies tonight and with this frosting recipe they turned out so much better! I love this recipe and the sheen of the hardened frosting on my sugar cookies. This had to be the easiest frosting recipe I’ve used and had a great taste too! Thank you for sharing. I will save it and use it again!
Thank you so much!