Mermaid Crumbl Cookies
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My friend, these Mermaid Crumbl Cookies are pure magic! Thick, soft, buttery sugar cookies topped with the dreamiest swirls of teal, aqua, and lavender buttercream that look like they came straight from under the sea. Plus, you can pipe all three frosting colors at once for that gorgeous mermaid effect, and the whole batch comes together so easily. These mermaid party desserts are colorful, fun, budget-friendly, and SO good.
More Crumbl cookie fun? You’ll also love these CopyCat Crumbl Chocolate Chip Cookies and these Crumbl Churro Cookies! Can we ever have enough Crumbl copycat recipes?
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Why You’ll Love These Mermaid Crumbl Cookies
- Skip the bakery prices! These mermaid crumbl cookies are easy to make at home and taste just as amazing.
- That three-color frosting swirl! Teal, aqua, and lavender all come out of the piping bag at once for the prettiest mermaid effect. So fun!
- Thick, soft, buttery cookie base. It holds up beautifully under a big pile of frosting, just like the real thing.
- Decorating is half the fun! Mermaid sprinkles, pearls, shimmer dust, and tiny shells make every cookie a little masterpiece.
Ingredients for Mermaid Crumbl Cookies (Piped 3-Color Frosting)
Sugar Cookie Base
- 1 cup unsalted butter, cold and cubed
- 1 cup granulated sugar
- 1 large egg
- 1 tablespoon vanilla extract
- 3 cups all-purpose flour
- 1 teaspoon baking powder
- 1/2 teaspoon baking soda
- 1/2 teaspoon salt
Vanilla Buttercream Frosting
- 1/2 cup unsalted butter, softened
- 2 cups powdered sugar
- 1-2 tablespoons heavy cream (or milk)
- 1 teaspoon vanilla extract
- Pinch of salt
- Gel food colors: teal, aqua, lavender
Store-Bought Frosting Option
- 2-3 tubs vanilla frosting
- Gel food colors: teal, aqua, lavender + pink
Mermaid Cookie Toppings
- Mermaid sprinkles, pearls, shimmer dust, tiny shells
Also love colorful cookies? Check out these Ultra Thick Spring Sprinkle Cookie Bars!
How to Make Mermaid Crumbl Sugar Cookies
- Preheat oven to 350°F. Line baking sheets with parchment paper.
- Cream 1 cup cold cubed butter and 1 cup granulated sugar until light and fluffy.
- Mix in 1 large egg and 1 tablespoon vanilla extract.
- Add 3 cups flour, 1 teaspoon baking powder, 1/2 teaspoon baking soda, and 1/2 teaspoon salt. Mix until a soft dough forms.
- Scoop 1/4-cup cookie dough balls (or 1/3-cup for extra-large cookies).
- Slightly flatten the tops.
- Bake 9-11 minutes for 1/4-cup cookies, or 11-13 minutes for 1/3-cup cookies. Edges should look set while centers stay soft and pale. Don’t overbake!
- Cool completely before frosting.
3-Color Mermaid Frosting Recipe
- Beat 1/2 cup softened butter until creamy.
- Add 2 cups powdered sugar, 1 teaspoon vanilla, a pinch of salt, and 1 tablespoon heavy cream.
- Then beat until smooth and fluffy. Add another tablespoon of cream if needed.
- Divide frosting into three bowls.
- Tint each bowl: teal, aqua, lavender or pink.
How to Pipe Mermaid Cookie Frosting
This is the fun part!
- Lay out a sheet of plastic wrap.
- Spoon three stripes of frosting side by side: teal, aqua, lavender.
- Roll the plastic wrap into a log and twist the ends.
- Snip one end of the plastic wrap.
- Insert the frosting log into a piping bag fitted with a round tip (or large open circle tip).
- Pipe swirls or mounds onto each cooled cookie. The colors will blend into a gorgeous mermaid swirl! I used an offset spatula to swirl the frosting after I piped it on.
Using Store-Bought Frosting
- Divide 2-3 tubs of vanilla frosting into three bowls.
- Tint each bowl teal, aqua, and lavender.
- Follow the same plastic-wrap piping method above.
- If frosting is too soft, chill 10 minutes before piping.
Decorating Your Mermaid Crumbl Cookies
- Pipe swirls or mounds onto each cooled cookie. Use an offset spatula to swirl if desired.
- Add mermaid sprinkles, pearls, shimmer dust, or tiny shells while the frosting is still soft.
- Chill 10 minutes for cleaner edges (optional).
Tips for the Best Mermaid Crumbl Cookies
- Cold butter is the secret. Because that’s what gives you that thick, soft Crumbl-style texture. So don’t soften it! Cut it into cubes straight from the fridge.
- Pull them out early. The cookies should look slightly underdone when you take them out. Pale edges, soft centers. As a result, they’ll firm up as they cool, and that’s how you get that chewy, bakery-style bite.
- Also, don’t over-swirl the frosting in the bag. You want the three colors to stay somewhat separate so they create that gorgeous mermaid swirl on the cookie. Gentle, steady pressure is the trick. 🙂
- Frosting getting soft? Just pop the piping bag in the fridge for 5 minutes. It’ll firm right back up and pipe these mermaid party desserts like a dream.
- Finally, make them big! These are Crumbl-style cookies, so go for that 1/4-cup scoop minimum. Bigger cookies mean thicker, softer centers.
Mermaid Cookie Variations and Fun Add-Ins
- Switch up the colors! Try ocean blues and greens for a deep-sea vibe, pastel pinks and purples for a fairy tale look, or galaxy colors with dark purple, navy, and silver shimmer.
- Add almond or coconut extract to the frosting for a tropical twist.
- Roll dough balls in sprinkles before baking for extra color in every bite.
- Cream cheese frosting version: Swap the buttercream for cream cheese frosting if you love that tangy sweetness. It pipes beautifully too!
- Mini mermaid cookies: Use a 2-tablespoon scoop instead and bake for 7-8 minutes. They’re adorable for party trays!
Love fun cookie ideas? You’ll also love these Ultimate Super Thick Mini M&M Chocolate Chip Cookies and these Holiday Oreo Cream Cheese Cookies!
Fun Times to Enjoy Mermaid Frosted Cookies
- Mermaid‑themed birthday parties — the ultimate match for sparkles, shells, and under‑the‑sea décor perfect for
- Pool parties & splash days — bright, summery, and perfectly on‑theme
- Beach or lake gatherings — a cute treat for seaside picnics or family days
- Baby showers — especially “Under the Sea” or “Little Mermaid” themes
- Bridal showers — adds a whimsical, pastel pop to dessert tables
- Summer camps & day‑camp celebrations — fun for theme days or craft parties
- Sleepovers & tween hangouts — magical, colorful, and selfie‑worthy
- Classroom or end‑of‑school parties — festive without being tied to a holiday
- Dance recitals or cheer events — especially when costumes match the colors
- Any dessert table needing a bright, whimsical moment — they’re instant eye‑catchers
How to Store Frosted Mermaid Cookies
Store frosted mermaid cookies in a single layer in an airtight container at room temperature for up to 3 days. Additionally, for longer storage, refrigerate for up to 5 days and let them come to room temperature for about 15 minutes before serving so the frosting softens back up.
Freezing: Freeze unfrosted cookies in a freezer bag for up to 3 months. Then thaw at room temperature and frost when you’re ready. Future you will be so happy. 🙂
Mermaid Crumbl Cookies FAQ
Can I make mermaid crumbl cookies ahead of time?
Yes! You can make the dough up to 2 days ahead and keep it in the fridge wrapped in plastic wrap. Let it sit at room temperature for about 10 minutes before scooping. Or bake the cookies up to 3 days ahead and store them unfrosted in an airtight container, then frost the day you plan to serve your mermaid party desserts.
What if I don’t have a piping bag?
A large zip-top bag works great. Just spoon the three-color frosting log inside, snip off one corner, and pipe away. You’ll still get a beautiful swirl.
Can I use cream cheese frosting on mermaid cookies?
Absolutely. Cream cheese frosting pipes well and tastes amazing on these cookies. Just make sure it’s thick enough to hold its shape, so add a little extra powdered sugar if needed.
How do I keep the frosting colors from blending too much?
Don’t over-squeeze the piping bag. Gentle, steady pressure keeps the color stripes distinct. Also, if the frosting starts to warm up and get soft, pop the bag in the fridge for 5 minutes before continuing.
So, are you ready to bring some mermaid magic into your kitchen? These thick, soft, buttery mermaid crumbl cookies with all those gorgeous frosting swirls are calling your name. Grab your piping bag and let’s make something beautiful! I hope these mermaid party desserts bring a splash of color and fun to your baking day.
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More Delicious Thick Cookie Recipes
- Holiday Oreo Cream Cheese Cookies (Soft, Festive & No-Chill!)
- Ultra Thick Spring Sprinkle Cookie Bars
- Oreo White Chocolate Brownie Cookies
- Ultimate Super Thick Mini M&M Chocolate Chip Cookies
- Thick Old-Fashioned Chocolate Chip Cookies
- “Phenomenal” Thick Milk Chocolate Chip Peanut Butter Cookies
Mermaid Crumbl Cookies
Equipment
- Baking sheets
- Parchment paper
- Electric mixer
- Piping bag with round tip
- Plastic wrap
- Offset spatula optional
Ingredients
Sugar Cookie Base
- 1 cup unsalted butter cold and cubed
- 1 cup granulated sugar
- 1 large egg
- 1 tablespoon vanilla extract
- 3 cups all-purpose flour
- 1 teaspoon baking powder
- ½ teaspoon baking soda
- ½ teaspoon salt
Vanilla Buttercream Frosting
- ½ cup unsalted butter softened
- 2 cups powdered sugar
- 1-2 tablespoons heavy cream or milk
- 1 teaspoon vanilla extract
- Pinch salt
- Gel food colors teal, aqua, lavender or pink
Toppings
- mermaid sprinkles
- pearls
- shimmer dust
- tiny shells
Instructions
Make the Cookies
- Preheat oven to 350°F. Line baking sheets with parchment paper.
- Cream 1 cup cold cubed butter and 1 cup granulated sugar until light and fluffy.
- Mix in 1 large egg and 1 tablespoon vanilla extract.
- Add 3 cups flour, 1 teaspoon baking powder, 1/2 teaspoon baking soda, and 1/2 teaspoon salt. Mix until a soft dough forms.
- Scoop 1/4-cup dough balls (or 1/3-cup for extra-large cookies). Slightly flatten the tops.
- Bake 9-11 minutes for 1/4-cup cookies, or 11-13 minutes for 1/3-cup cookies. Edges should look set while centers stay soft and pale.
- Cool completely on baking sheets before frosting.
Make the Frosting
- Beat 1/2 cup softened butter until creamy.
- Add 2 cups powdered sugar, 1 teaspoon vanilla, a pinch of salt, and 1 tablespoon heavy cream. Beat until smooth and fluffy. Add more cream if needed.
- Divide frosting into three bowls. Tint each bowl: teal, aqua, lavender.
Pipe the 3-Color Frosting
- Lay out a sheet of plastic wrap. Spoon three stripes of frosting side by side: teal, aqua, lavender.
- Roll the plastic wrap into a log and twist the ends. Snip one end.
- Insert the frosting log into a piping bag fitted with a round tip.
- Pipe swirls or mounds onto each cooled cookie. Use an offset spatula to swirl if desired.
Decorate
- Add mermaid sprinkles, pearls, shimmer dust, or tiny shells while frosting is still soft.
- Chill 10 minutes for cleaner edges (optional).
