Frosted Sugar Cookie Bars

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Frosted Sugar Cookie Bars- A soft sugar bar cookie loaded with sprinkles covered with a thick layer of vanilla frosting!

frosted sugar cookie bar on a plate


No dessert goes over better than a cookie bar I believe. 

Now stir in sprinkles and frost them and you have a winner on your hands.

Sugar cookie bars are thicky and chewy with lots of sprinkles stirred in. Top it off with the best vanilla buttercream frosting. No one is going to pass these up.

Why You Will Love This Recipe

  • Perfect For Any Holiday! Use whatever colored sprinkles you want to make these festive for a holiday. Red and green for Christmas! Pink and red for Valentine’s Day! You get the idea.
  • Easier Than Sugar Cookies – Speaking of holidays, cut out sugar cookies are great. But let’s face it can be a bit time consuming! These are much faster and easier to make!
  • Can Leave Unfrosted – Make these even faster by skipping the buttercream frosting!

Recipe Ingredients

Here is what you need to make these frosted sugar cookie bars:

  • Butter – If you don’t have unsalted butter, then you can substitute salted butter, but reduce the salt in the recipe. You can read more here about Unsalted Butter Vs. Salted Butter In Baking.
  • Granulated sugar – This will be to sweeten the bars but also to help aerate the mixture as it gets creamed together with the butter. 
  • Egg + 1 Egg Yolk – You need one large egg, at room temperature to help bring the batter together and to help tenderize. The extra egg yolk will add extra fat, making a richer more tender bar. You can add your eggs to a bowl of warm water for 10 minutes before starting. 
  • Vanilla – Pure vanilla extract is always best for flavor!
  • AP flour – Be sure to measure your flour correctly by spooning it into your cup and leveling it off so you don’t end up with dry sugar cookie bar. If you do not own a scale, then make sure to give this post a read on How To Measure Flour.
  • Leavening Agents – Both baking powder and baking soda! Don’t mix them up. This will help the bars rise.  You can read more here about baking powder vs. baking soda
  • Salt – Salt is always needed to help balance all the flavors. I love kosher salt as I think it has a more pure salt taste than regular table salt. You can read more here about The Role Of Salt In Baking.
  • Cornstarch – This helps to soften the texture of the bars.
  • Sprinkles – Because um why not?! Sprinkles make it better. These will get stirred into the batter.
  • Confectioners sugar – I use this in the frosting. I used to sift my sugar but now I just make sure to mix it well enough to ensure it’s fluffy and smooth. 
  • Heavy cream – To thin out the frosting and add some richness.
ingredients for frosted sugar cookie bars

Recipe How To:

  1. Prepare your pan by lining it with aluminum foil. These bars got enough butter in them, so don’t worry about greasing it. This recipe is made in either 8×8 pan or 9×9 pan, but in this photo I was making a double batch so I was using a 9×13 pan.
  2. Measure out your dry ingredients and whisk them together. Set the bowl aside.
  3. In a second bowl with a hand mixer or your stand mixer, cream your butter for 1 minute.
  4. Add your sugar and continue to cream on medium speed until light and fluffy about 2 minutes.
  5. Mix in your egg + egg yolk.
  6. Stir in your vanilla (I used vanilla bean paste for ultimate vanilla flavor)
frosted sugar cookie bar step by step photos of making batter

      7. Mix in your flour in 3 batches. The mixture will be VERY thick.

      8. Mix in your sprinkles.

      9. Add the batter to your prepared pan. Use plastic wrap to press the mixture down into the pan.

      10.  Bake for 25 minutes. Allow to cool before frosting! I used this vanilla buttercream frosting.

step by step photos of making frosted sugar cookie bars

Tips On Making These Bars

  1. Be sure to measure your flour correctly. Over measuring will result in a dense cake like bar instead of a soft chewy one.
  2. Bring your room eggs to room temperature quickly by placing them in a bowl of warm water for 10 minutes. 
  3. Give your eggs a quick whisk before adding to the butter. If you don’t the egg yolks will start to “cook” and you will notice your mixture will look slightly curdled and lumpy. 
  4. Be careful to not over cream your butter and sugar. Overcreaming will result in too much air being incorporated into the batter, which will result in a cakelike texture.
  5. Add your dry ingredients in 3 batches, so it can be evenly incorporated.

Recipe FAQ’s

What kind of sprinkles should I use?

For these bars, you want to use regular old sprinkles or jimmies as they are called. You want to avoid using non-pareils (like these) because their color will bleed into the dough when they bake. I love using these type of sprinkles. These are the same sprinkles I used in my Funfetti Sheet Cake

What kind of pan should I use?

You can use either an 8×8 pan (for thickest bars), 9×9 pan, or a double batch in a 9×13 pan.

What does the cornstarch do?

The key to the bar’s soft chewy texture lies in the secret ingredient: cornstarch. Cornstarch is typically used in savory dishes to thicken a sauce or soup.  Cornstarch will work in the same manner in keeping these bars wonderfully thick and soft. 

frosted sugar cookie bar on a plate with a fork


I store these bars, unfrosted, covered at room temperature the day before you plan to serve them. And store the frosting in the fridge (I make mine up to 5 days ahead of time). You may need to re-whip the frosting before spreading onto the bars. 

When ready to serve, frost the bars and enjoy!

Or you can store them longer, unfrosted, in the freezer for up to 3 months. Just wrap well in plastic wrap and/or store in a plastic bag. I let them thaw at room temperature before serving.

frosted sugar cookie bars

More Recipes To Enjoy

Frosted Sugar Cookie Bars

A soft, chewy sugar cookie bar loaded with sprinkles and topped with thick layer of vanilla buttercream frosting. Then topped with even more sprinkles!
5 from 8 votes
Print Pin Rate
Course: Dessert
Cuisine: bars
Prep Time: 25 minutes
Cook Time: 25 minutes
Total Time: 50 minutes
Servings: 16 bars



  • 1/2 cup 115g unsalted butter, softened to room temperature
  • 3/4 cup 150g granulated sugar
  • 1 large egg + 1 egg yolk*
  • 2 teaspoons vanilla extract
  • 1 and 1/2 cups 190g spoon & leveled all-purpose flour
  • 1/4 teaspoon salt
  • 1 teaspoon baking powder
  • 1/2 teaspoon baking soda
  • 1 and 1/2 teaspoons cornstarch
  • 1/2 cup 80g rainbow sprinkles (not nonpareils)*
  • 2 1/2 sticks unsalted butter softened to room temperature
  • 2 1/2 cups 270g confectioners’ sugar
  • 2 Tablespoons 45ml heavy cream or half-and-half*
  • 2 teaspoons vanilla extract
  • salt to taste


  • Food coloring I used blue, and a a few drops of a purple
  • Sprinkles extra, for topping the bars


  • For the bars: Preheat oven to 350F degrees. Line an 8-inch or 9-inch square baking pan with parchment paper, making sure to leave enough overhang on the sides. Set aside.
  • In a large bowl using a hand-held mixer or stand mixer fitted with a paddle attachment, cream the softened butter for about 1 minute on medium speed. Get it nice and smooth, then add the sugar on medium speed until fluffy and light in color. Beat in egg, egg yolk, and vanilla. Scrape down the sides as needed.
  • In a medium bowl, whisk together the flour, salt, baking powder, baking soda, and cornstarch. With the mixer running on low speed, slowly add the dry ingredients to the wet ingredients in 3 different parts. The dough is quite thick. Once combined, gently fold in 1/2 cup sprinkles using a rubber spatula (or by mixing on low speed).
  • Press the cookie dough evenly into the prepared baking pan. Bake for 25-26 minutes or until very lightly browned on top. (My bars puffed up while baking, then collapsed and cracked a bit on top. It did not seem to affect the overall yumminess). You want the cookie bars to be extra soft, so careful not to overbake. Allow the bars to cool completely on a wire rack at room temperature before frosting.
  • For the frosting: If you don’t want a super thick layer of frosting as pictured, halve the frosting recipe. With a handheld or stand mixer fitted with a paddle attachment, beat the butter on medium speed until creamy – about 2 minutes. Add confectioners’ sugar and beat for another 2-3 minutes until fully incoroporated. Scrape down as needed. Then add in the cream, and vanilla extract with the mixer running on low. Increase to high speed and beat for 8 full minutes. Add a pinch of salt if frosting is too sweet. I usually add anywhere between 1/8 – 1/4 teaspoon of salt. Beat in food coloring, if using.
  • Remove cooled bars from the baking pan using the aluminum foil overhang on the sides. Frost the bars with a thick layer of frosting and decorate with extra sprinkles if desired. Cut into squares. Use a very sharp knife and wipe off with a paper towel between each cut to make neat, even cuts.
  • Store bars in an airtight container at room temperature for up to 2 days and in the refrigerator up to 5.
  • * To soften your butter quickly, cut into small pieces, and let sit out for 30-45 minutes. Go catch up on your favorite television and when you come back the butter should be perfectly softened ready to go.
  • *Room temperature egg and egg yolk preferred. To bring the egg to room temperature quickly, place in a warm glass of water for about 10 minutes as you get the other ingredients ready. Or just set out when you set out the butter to soften 1 hour ahead of time.
  • *Please use regular sprinkles (aka “jimmies”) in the cookie bar base. Nonpareils (the little balls) will bleed their color and turn the sugar cookie dough green/purple/brown. I order my sprinkles in bulk here.
  • *Heavy Cream or half-and-half is preferred for creamiest, fluffiest frosting. I have used milk when in a pinch and it still came out delicious!
  • *You can try a different size pan. I originally tried putting it in a 9×13 pan but wasn’t happy with the thickness of the bar and went back to my trusty 8×8 pan. Baking time would be less if in a bigger pan.


  • Tools:8×8 pan | Stand mixer | Sprinkles
  • Pan Size: You can use either an 8×8 or 9×9 pan (will be a bit thinner), or make a double batch and put into a 9×13 pan. Bake for about 35 minutes in a 9×13 pan.
  • Make Ahead/Storage: I store these bars, unfrosted, covered at room temperature the day before you plan to serve them. And store the frosting in the fridge (I make mine up to 5 days ahead of time). You may need to re-whip the frosting before spreading onto the bars. When ready to serve, frost the bars and enjoy! Or you can store them longer, unfrosted, in the freezer for up to 3 months. Just wrap well in plastic wrap and/or store in a plastic bag. I let them thaw at room temperature before serving.
  • Adapted from Sally’s Baking Addiction
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  1. 5 stars
    Yummy and super easy to make!

    1. Thanks Mochi …so glad you loved them!

  2. Shadi Hasanzadenemati says:

    5 stars
    Love all the ingrea dients, can’t wait to try this! It looks so delicious and easy!

  3. 5 stars
    Yum!! This is one of my kids’ favorite desserts to make! It’s everything we love about a sugar cookie but so much better thanks to the frosting and the added ingredients for the bars!

    1. That’s great they’re already having fun in the kitchen =)

  4. Maria San Juan says:

    5 stars
    My kids and I are excited to make this for Christmas! Thanks for sharing! This looks so yummy!

  5. 5 stars
    Oh how wonderful! My daughter would have such fun baking these cookie bars with me. Especially with all the sprinkles and the vanilla frosting. Yum!

  6. 5 stars
    Whipped up a batch of these this afternoon and they do not disappoint! Easy and delicious; exactly what I needed to cure my sweet tooth!

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