The cutest sprinkle-adorned unicorn bars will make your little one's birthday extra special. A tender buttermilk funfetti cake is topped with a creamy BLUE buttercream that's topped with more sprinkles. Perfect for parties!
Looking for an adorable way to celebrate your little one's birthday? Make unicorn bars! If you're a fan of funfetti, you will love this soft and sweet, sprinkle-laden cake. These adorable treats are perfect for any occasion, from a backyard birthday to an end-of-school picnic, making them an ideal choice for littles and the grown-ups who love them. So grab a package of pretty sprinkles and pick up a package of festive plates, and you'll be on your way to creating the best party ever.
For more kid-friendly birthday cakes, try a vanilla buttermilk cake or a gluten free chocolate chip cake!
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Kids LOVE These Bars!
My kids seriously cannot get enough of these bars, and there's so much to love about them: A sweet vanilla cake packed with pretty sprinkles that's topped with a vibrant blue buttercream icing and even more sprinkles. They're also fun to eat because they're cut into handheld squares, making them easy for little hands to hold. When you want to do something a bit more than a traditional cake, turn to unicorn bars—your kids will be thrilled.
- They're cute. What kid doesn't love sprinkles, right? You can also decorate them with mini unicorns or get sprinkles that contain unicorn shapes (yes, they exist!).
- Whimsical and fun. From sprinkles to colored frosting, these bars are packed with all the glittery goodness little hearts adore.
- Kid-friendly. Not only are kids enchanted by unicorn bars, but the recipe is easy enough that they can get involved in making them!
- Customizable. Choose your own adventure and play around with the color of food coloring and add sprinkles to your heart's content.
Why Are They Called Unicorn Bars?
I call these treats unicorn bars because they are sparkly and fun, just like a unicorn! There's a touch of magic in the soft and fluffy cake that's topped with equally soft and fluffy buttercream. They are guaranteed to bring a little joy in every bite and will lend even the gloomiest afternoon a burst of sunshine.
What You'll Need
You'll find easy ingredients on this list—nothing fancy, but they come together to create something truly special. Make sure to scroll down to my recipe card at the bottom of this post for the full ingredient amounts and instructions.
- Butter - Unsalted butter, softened to room temperature first, is best.
- Granulated sugar
- Eggs - I used large eggs for this cake.
- Vanilla - You can add pure vanilla extract or vanilla bean paste for a little vanilla-y kick.
- Dry ingredients - All-purpose flour, baking powder, and fine salt.
- Buttermilk - I recommend using real buttermilk if you can get it. Otherwise, you can make a buttermilk substitute by adding 1 tablespoon of white vinegar to 1 cup of milk.
- Frosting - Butter, powdered sugar, (blue) food coloring, and milk if needed.
- Sprinkles - I use rainbow sprinkles in the cake batter and pretty, shaped sprinkles for the top of the cake. You can use any sprinkles you prefer.
How to Make Unicorn Bars
Follow along with my photos below so you'll get a general idea of how to make these bars. Let the cake cool fully before adding the frosting, and you can frost it right in the pan if you prefer. Then, cut the bars out of the pan and place them on a serving plate.
- Prep: Preheat the oven to 350℉ and grease a 9x13-inch baking pan and line it with parchment paper.
- Cream butter: In a large bowl, cream the butter and sugar until fluffy.
- Add eggs: Beat in the eggs one at a time, then beat in the vanilla.
- Make dry mix: Whisk together the dry ingredients.
- Add to butter: On low, mix the dry mix into the butter mixture.
- Add buttermilk: Mix in the buttermilk until combined.
- Stir in sprinkles: Fold in the rainbow sprinkles.
- Place in pan. Pour the batter into the prepared pan.
- Bake. Bake the cake for about 45 minutes, then cool it completely.
- Make frosting: Cream the butter and add the powdered sugar.
- Color: Beat in the food coloring.
- Assemble: Frost the cake and decorate it with sprinkles!
Baking Tip: Make It Gluten-Free
Need to make gluten-free unicorn bars for your gluten-free little one? Substitute 3 ½ cups (420 grams) of gluten-free flour blend for the all-purpose flour. Let the batter rest in the pan for about 20 minutes before baking to fully hydrate the flour.
Tips & Variation Suggestions
- Shake the buttermilk. Buttermilk, like yogurt, needs a good shake or stir before using it. So, exercise those muscles and shake up the buttermilk before adding it to the batter.
- Use room-temperature ingredients. Especially important in the frosting, but also for the cake: Room temperature ingredients, particularly the butter, will easily blend with the other ingredients.
- For the best texture: If you've kept the cake in the fridge, bring it to room temperature on the counter before serving. I try to allow about 15-30 minutes for the cake to "warm up" after it's been in the fridge. You will not regret it!
- Make it a chocolate chip cake. You can use the cake base to make chocolate chip unicorn bars! Instead of (or in addition to?) sprinkles, add mini chocolate chips to the cake batter.
- Different frosting colors. I love blue frosting but you really could use any color you like! Pink would be very pretty, or you could do a rainbow combination of different-colored buttercream.
Proper Storage
- Counter - Cover the cake with foil and keep it on the counter for up to 3 days.
- Fridge - The cake, covered or in an airtight container, will keep well in the fridge for up to 1 week. Let it sit on the counter for about 30 minutes before serving if it's been in the fridge.
- Freezer - Store the unfrosted cake by wrapping it tightly in a layer of plastic then a layer of foil, and placing it in the freezer for up to 2 months. Thaw the cake in the fridge before frosting. Or place the assembled cake or pieces of cake in a freezer-safe container and store it in the freezer for up to 2 months. The texture of the frosting will not be as fluffy when it's thawed, but it will still taste good. Defrost the cake in the fridge before serving.
More Pretty Cake Recipes
If you try this recipe, please let me know! And if you have any questions, always feel free to reach out in the comments or by email. I hope you love it! ❤️
Unicorn Bars
Ingredients
- 1 cup unsalted butter , at room temperature
- 2 cups granulated sugar
- 4 large eggs
- 1 tablespoon pure vanilla extract
- 3 cups all purpose flour
- 1 tablespoon baking powder
- ¼ teaspoon fine sea salt
- 1 ⅓ cups buttermilk , well-shaken
- ¼ cup rainbow sprinkles
Frosting
- ¾ cup unsalted butter , at room temperature
- 4 cups powdered sugar , sifted
- 1 teaspoon blue food coloring
- 1-2 tablespoons milk , as needed
- decorative sprinkles
Instructions
Make the Cake
- Preheat the oven to 350℉ and grease a 9x13-inch baking pan. Line it with parchment paper for easy removal.
- In a large bowl, beat the 1 cup unsalted butter and 2 cups granulated sugar together using an electric mixer until light and fluffy, about 5 minutes. Beat in the 4 large eggs one at a time, then add the 1 tablespoon pure vanilla extract.
- In another large bowl, whisk together the 3 cups all purpose flour, 1 tablespoon baking powder, and ¼ teaspoon fine sea salt. With the mixer on low, add half the flour mixture to the butter and egg mixture and beat until just combined. Add the 1 ⅓ cups buttermilk and mix well to combine. Add the remaining flour mixture and beat until just combined, scraping down the bowl as necessary. Fold in the ¼ cup rainbow sprinkles.
- Pour batter into the prepared pan, place in the oven, and bake for about 45 minutes, until a tester inserted in the middle of the cake comes out clean. Remove from oven and place on a rack to cool completely in the pan.
Make the Frosting
- In a large bowl, cream the room temperature ¾ cup unsalted butter until fluffy. Beat in the 4 cups powdered sugar, then add the 1 teaspoon blue food coloring, beating until well incorporated. If the frosting seems a little dry, add 1-2 tablespoons milk, and beat until fluffy.
- Assembly: You may leave the cake in the pan or gently remove it (I kept it easy and left it in the pan). Frost the top of the cooled cake with the frosting, then liberally cover the top with decorative sprinkles. Cut the cake into squares to serve.
Notes
-
- Shake the buttermilk. Buttermilk, like yogurt, needs a good shake or stir before using it. So, exercise those muscles and shake up the buttermilk before adding it to the batter.
-
- Use room-temperature ingredients. Especially important in the frosting, but also for the cake: Room temperature ingredients, particularly the butter, will easily blend with the other ingredients.
-
- For the best texture: If you've kept the cake in the fridge, bring it to room temperature on the counter before serving. I try to allow about 15-30 minutes for the cake to "warm up" after it's been in the fridge. You will not regret it!
-
- Make it a chocolate chip cake. You can use the cake base to make chocolate chip unicorn bars! Instead of (or in addition to?) sprinkles, add mini chocolate chips to the cake batter
-
- Different frosting colors. I love blue frosting but you really could use any color you like! Pink would be very pretty, or you could do a rainbow combination of different-colored buttercream.
- Counter - Cover the cake with foil and keep it on the counter for up to 3 days.
- Fridge - The cake, covered or in an airtight container, will keep well in the fridge for up to 1 week. Let it sit on the counter for about 30 minutes before serving if it's been in the fridge.
- Freezer - Store the unfrosted cake by wrapping it tightly in a layer of plastic then a layer of foil, and placing it in the freezer for up to 2 months. Thaw the cake in the fridge before frosting. Or place the assembled cake or pieces of cake in a freezer-safe container and store it in the freezer for up to 2 months. The texture of the frosting will not be as fluffy when it's thawed, but it will still taste good. Defrost the cake in the fridge before serving.
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