Easy Frosted Sugar Cookie Bars

Delicious Frosted Sugar Cookie Bars that are gluten-free and egg-free! Soft, buttery cookie base with creamy buttercream frosting. Perfect for busy families!

You know that moment when you’re craving something sweet but the thought of rolling out cookie dough and cutting individual shapes makes you want to crawl back into bed? Yeah, me too. That’s exactly why these Frosted Sugar Cookie Bars have become my go-to treat when I need something special without the fuss.

I created this gluten free sugar cookies recipe on a particularly hectic Tuesday when my daughter asked if we could bake together. Between laundry piles and dinner prep, traditional cookies felt impossible.

But bar cookies? Now we’re talking! You simply press the dough into a pan, bake, frost, and slice. No rolling pins, no cookie cutters, no flour everywhere (well, maybe just a little).

These gluten free cookie bars deliver all the nostalgic joy of classic sugar cookies with a fraction of the effort. The buttery base stays soft and chewy, while the silky buttercream frosting adds that bakery-style finish. Plus, they’re egg-free using a simple replacer, making them accessible for even more dietary needs.

Whether you’re new to gluten-free baking or juggling a million things (or both!), this sugar cookie bar recipe will become your new favorite shortcut to homemade happiness.

Frosted Sugar Cookie Bars Ingredients

For the Cookie Bars:

• 1 ½ cups (222g) gluten free flour blend
• 1 ½ teaspoons baking powder
• ¼ teaspoon salt
• ½ cup (113g) unsalted butter, room temperature
• ½ cup (100g) granulated sugar
• ½ cup (100g) light brown sugar, packed
• 1 tablespoon Bob’s Red Mill Egg Replacer mixed with 2 tablespoons water
• 1 teaspoon vanilla extract

For the Buttercream Frosting:

• ½ cup (113g) unsalted butter, room temperature
• 1 ½ cups (180g) powdered sugar
• 1-2 tablespoons whole milk
• Food coloring (optional)

Instructions

Step 1: Preheat your oven to 350°F. Line a square baking pan with parchment paper and set it aside. Trust me, the parchment makes removal so much easier!

Step 2: In a small bowl, whisk together the gluten free flour blend, baking powder, and salt. Set this dry mixture aside while you work on the good stuff.

Step 3: Using a hand mixer or stand mixer fitted with the paddle attachment, cream the butter with both sugars until well combined. This usually takes about 2 minutes. Add the prepared egg replacer and vanilla extract, then continue beating until smooth.

Step 4: Add your dry ingredients to the butter mixture and mix on low speed until just combined. Don’t overmix here—we want tender Frosted Sugar Cookie Bars, not tough ones!

Step 5: Pour the dough into your prepared pan and spread it evenly. Bake for 16-18 minutes, or until the edges turn slightly golden brown. The center might look a touch underdone, but it’ll firm up as it cools.

Step 6: Let the cookie base cool completely in the pan before frosting. I know waiting is hard, but warm cookies plus buttercream equals a melty mess!

To Make the Buttercream Frosting:

Step 7: Using your mixer, beat the butter until it’s smooth and creamy—about 1 minute does it.

Step 8: Add the powdered sugar and continue mixing until fully combined. The mixture will look crumbly at first, but keep going!

Step 9: Add milk one tablespoon at a time, beating after each addition until you reach your desired consistency. For spreading, you want it smooth but not too thin. If you’re using gel food coloring, mix it in now.

Step 10: Spread the frosting over your cooled cookie base, then slice into bars. I usually cut mine into 16 squares, but you can make them bigger or smaller depending on your crowd.

Why Frosted Sugar Cookie Bars Recipe Works

The magic behind these gluten free cookie bars lies in a few key techniques. First, using both granulated and brown sugar creates the perfect texture—soft and chewy without being cakey. According to research on gluten-free baking chemistry, the right sugar ratio helps compensate for the lack of gluten structure.

Second, the egg replacer keeps these Frosted Sugar Cookie Bars tender without compromising on texture. I’ve tested this recipe with actual eggs too, and honestly? The egg-free version is just as delicious, which makes this meaningful eats gluten free sugar cookies recipe perfect for friends with multiple allergies.

Finally, letting the bars cool completely before frosting prevents that frustrating scenario where your beautiful frosting slides right off. Patience pays off here!

Substitutions & Swaps For Your Frosted Sugar Cookie Bars

Flour Blend: I recommend a 1:1 gluten-free flour blend that contains xanthan gum (like Bob’s Red Mill or King Arthur Measure for Measure). If your blend doesn’t include it, add ½ teaspoon of xanthan gum to prevent crumbly bars.

Egg Replacer: Can’t find Bob’s Red Mill? Use one large egg instead, or try a flax egg (1 tablespoon ground flaxseed mixed with 2.5 tablespoons water, let sit 5 minutes). The texture will vary slightly, but they’ll still be delicious!

Butter: For dairy-free gluten free sugar cookies, swap in your favorite vegan butter stick (I like Miyoko’s or Earth Balance). Make sure it’s room temperature for proper creaming. You’ll also need dairy-free milk for the frosting.

Sugar: You can use all granulated sugar if that’s what you have, though you’ll lose a bit of that chewy depth that brown sugar provides. Don’t substitute with coconut sugar—it’ll change the texture too much in this sugar cookie bar recipe.

Frosting: Not a frosting person? These bars are lovely with just a dusting of powdered sugar on top. Or try a simple glaze made with powdered sugar and milk.

Troubleshooting Tips

Bars are too crumbly: Your flour blend likely needs xanthan gum, or you may have overbaked them slightly. Check your oven temperature with an oven thermometer—many run hot!

Dough is too dry: Gluten-free flours can vary in absorption. If your dough seems crumbly before baking, add an extra tablespoon of butter or a teaspoon of milk to bring it together.

Frosting is too stiff: Simply add more milk, a teaspoon at a time, until it reaches spreading consistency. Too thin? Add more powdered sugar.

Edges are browning too quickly: Your oven might be running hot, or you’re baking on a dark pan, which conducts more heat. Try reducing the temperature by 25°F next time, or use a light-colored pan.

Bars stick to the pan: This is why parchment paper is your best friend! If you forgot it, let the bars cool for 10 minutes, then run a knife around the edges before attempting removal.

Storage & Meal Prep

These frosted gluten free cookie bars stay fresh at room temperature in an airtight container for up to 3 days. If your kitchen is particularly warm, pop them in the fridge to keep the frosting from getting too soft—they’ll last up to 5 days that way.

For longer storage, freeze the unfrosted bars wrapped tightly in plastic wrap and aluminum foil for up to 3 months. Thaw at room temperature, then make fresh frosting when you’re ready to serve. I actually prefer this method for meal prepping treats!

Pro tip: Freeze individual frosted bars on a baking sheet until solid, then transfer to a freezer bag. Pull out one or two whenever you need a quick dessert or lunchbox treat. They thaw in about 30 minutes on the counter.

Planning a party? You can make these gluten free sugar cookies a day ahead. Just store them unfrosted in the fridge overnight, then frost them the morning of your event. The texture actually improves after a rest!

Serving Suggestions

I love serving these sugar cookie bars at casual gatherings because they’re so easy to grab and go. Cut them into small squares for a dessert platter alongside fresh berries and maybe some easy gluten-free chicken taquitos for a fun party spread.

For a special breakfast treat (don’t judge!), pair a bar with your morning coffee. The buttery sweetness is surprisingly perfect with a dark roast.

Kids adore decorating these themselves. Set out bowls of sprinkles, mini chocolate chips, or colored sugar and let them go wild on their own square. It’s a fantastic rainy-day activity that doubles as dessert.

During the holidays, tint the frosting red and green, or add festive sprinkles. For birthdays, match your party colors. Valentine’s Day? Pink frosting with heart sprinkles. These bars are your blank canvas!

Craving something heartier? Check out this easy protein gluten-free bread recipe to balance out your baking session with something more substantial.

Fun Variations

Lemon Bars: Add 1 tablespoon of lemon zest to the cookie dough and 1 teaspoon to the frosting. Use lemon juice instead of milk in the frosting for a bright, citrusy twist on these gluten free cookie bars.

Chocolate Lover’s Version: Mix ½ cup mini chocolate chips into the dough before baking. Top with chocolate buttercream frosting instead of vanilla.

Almond Joy Inspired: Add ½ teaspoon almond extract to the dough, then top the frosted bars with toasted coconut flakes and a drizzle of melted chocolate.

Kid-Friendly Funfetti: Fold ¼ cup rainbow sprinkles into the dough before baking. It’s like a party in every bite of these meaningful eats gluten free sugar cookies!

Dairy-Free Option: As mentioned in substitutions, use vegan butter and non-dairy milk throughout. The results are just as soft and delicious.

Nut Butter Swirl: Before baking, drop small spoonfuls of almond or sunflower seed butter onto the dough and swirl with a knife for a marbled effect.

Frosted Sugar Cookie Bars FAQs

Final Thoughts

There’s something wonderfully comforting about pulling a pan of these gluten free cookie bars from the oven. The kitchen smells like vanilla and butter, and you know that in just a bit, you’ll have a treat that rivals any bakery—without leaving your house or spending a fortune.

I hope this sugar cookie bar recipe becomes a staple in your kitchen like it has in mine. It’s forgiving, customizable, and most importantly, it makes people smile. Whether you’re baking for a crowd, a cozy night in, or just because it’s Tuesday and you deserve something sweet, these frosted beauties have got you covered.

Now, if you’ll excuse me, I have a pan of these calling my name from the kitchen counter. The frosting is perfectly set, and I think quality control is definitely in order. Happy baking, friend!