One-Bowl Gluten-Free Cookie Bars

These gluten-free cookie bars come together in one bowl with no mixer and no chilling. They bake up soft in the middle with crisp, golden edges.

The chocolate chips stay melty and the whole thing tastes like a really good bakery cookie, not like a compromise.

Why This One Stays in the Rotation

I keep coming back to these bars because they deliver that thick, chewy texture I want from a cookie bar, with zero aftertaste. Oat flour and almond flour do the heavy lifting so you never get that dry, sandy crumb some gluten-free bakes have.

They stay soft for days on the counter, which makes them perfect for lunchboxes or a last-minute dessert. The batter takes about ten minutes to mix, and then the oven does the rest.

Ingredients

• 1 cup (2 sticks) unsalted butter, melted: I use salted butter and cut back on added salt if that is what you have.
• 1 cup packed light brown sugar: dark brown sugar works too, giving a deeper caramel note.
• 1/2 cup granulated sugar
• 2 large eggs: room temperature eggs mix in more smoothly.
• 2 tsp vanilla extract
• 1 1/2 cups gluten-free oat flour: certified gluten-free is important here.
• 1 cup almond flour: blanched super-fine almond flour gives the best texture.
• 1 tsp baking soda
• 1/2 tsp fine sea salt: reduce to 1/4 tsp if your butter is salted.
• 2 cups semi-sweet chocolate chips: use dairy-free chips to make these entirely dairy-free.

Variations / Substitutions

• Make them nut-free: swap the almond flour for an equal amount of additional oat flour.
• Dairy-free: use a good vegan butter stick and dairy-free chocolate chips.
• Swap the chips: white chocolate and dried cranberries, or chopped dark chocolate and toasted pecans work beautifully.
• Gluten-free flour blend: a 1:1 all-purpose gluten-free flour can replace both flours, though the bars will be slightly less tender.

If you enjoy this, try my Gluten-Free Peanut Butter Brownie Bars.

How to Make One-Bowl Gluten-Free Cookie Bars

Step 1: Mix the Wet Ingredients

Heat your oven to 350°F (177°C). Line a 9×13-inch metal baking pan with parchment paper, leaving a little overhang so you can lift the bars out later.

In a large bowl, whisk the 1 cup melted butter with 1 cup brown sugar and 1/2 cup granulated sugar until no dry lumps of sugar remain. Whisk in the 2 large eggs and 2 teaspoons vanilla extract, just until the mixture is smooth and glossy.

The batter will look a little thick now. That is a good sign because it means the sugar is starting to dissolve, which leads to a chewier bar.

Step 2: Add the Dry Ingredients

Sprinkle the 1 1/2 cups oat flour, 1 cup almond flour, 1 teaspoon baking soda, and 1/2 teaspoon salt right on top of the wet mixture. Stir with a wooden spoon or a flexible spatula until no streaks of flour remain.

The dough will pull together into a thick, slightly sticky mass. You might need to use a folding motion to work the last bit of flour in without overmixing.

Step 3: Fold in the Chocolate Chips

Add the 2 cups chocolate chips and fold just until they are evenly distributed. A few rogue chips on the bottom of the bowl are totally fine.

Press the dough into the prepared pan in an even layer. Damp fingertips work well here to keep the dough from sticking to your hands, and it helps you push it all the way into the corners.

Step 4: Slice and Serve the Bars

Bake on the center rack for 22 to 25 minutes, until the edges are deeply golden and the center looks set but still a little soft. A toothpick inserted in the middle will come out with a few moist crumbs, not wet batter.

Let the bars cool in the pan on a wire rack for 10 minutes, then use the parchment to lift them out. Slice into squares and serve while they are still warm, when the chocolate chips are at their meltiest. The crumb will be tender and pale golden with crisp edges.

Tips for the Best Cookie Bars

• Use certified gluten-free oat flour. Regular oat flour can carry traces of wheat, and for these bars to work for everyone, that certification matters.
• Slightly underbaking is your friend. The bars continue to set as they cool, so pulling them out when the center still appears a touch soft guarantees a fudgy, not dry, texture.
• For the cleanest cuts, let the bars cool completely on a wire rack before slicing. A warm bar tastes incredible but cuts can get messy.

Bake times by pan:

Storing Leftovers

• Refrigerate: Keep bars in an airtight container at room temperature for up to 3 days or in the fridge for up to a week. They stay soft either way.
• Reheating: A 10-second zap in the microwave revives that just-baked gooeyness in the chips.
• Freeze: Layer cooled bars between sheets of parchment in a freezer bag and freeze for up to 2 months. Thaw at room temperature.

Frequently Asked Questions

Can I use coconut oil instead of butter?

You can, but the bars will spread more and lose a little of their chewy edge. Use refined coconut oil if you do not want a coconut flavor.

Why did my bars turn out crumbly?

The most common reason is overbaking. Even a few extra minutes can dry them out. Also check that you packed the brown sugar and measured the flour lightly, not scooped and packed it down.

Can I make these with coconut sugar?

Yes, substitute the granulated sugar and brown sugar with an equal amount of coconut sugar. The flavor will be deeper and the bars will be a bit less chewy, but still good.

Do I need to chill the dough?

No, this recipe is designed to go straight into the oven. Chilling would firm the butter and change the texture.

One-Bowl Gluten-Free Cookie Bars Recipe

Print Recipe Pin Recipe

Prep Time 10 minutes mins

Cook Time 25 minutes mins

Total Time 35 minutes mins

Servings: 16 servings

Calories: 285

Ingredients Method Notes

Ingredients

  

• 1 cup (2 sticks) unsalted butter, melted
• 1 cup packed light brown sugar
• 1/2 cup granulated sugar
• 2 large eggs
• 2 tsp vanilla extract
• 1 1/2 cups gluten-free oat flour
• 1 cup almond flour
• 1 tsp baking soda
• 1/2 tsp fine sea salt
• 2 cups semi-sweet chocolate chips

Method

 

1. Heat oven to 350°F (177°C). Line a 9×13-inch metal pan with parchment. Whisk melted butter, brown sugar, and granulated sugar until smooth. Whisk in eggs and vanilla.
2. Add oat flour, almond flour, baking soda, and salt directly to the bowl. Stir until just combined.
3. Fold in chocolate chips. Press dough evenly into the prepared pan.
4. Bake 22-25 minutes until edges are golden and center looks set. Cool 10 minutes in the pan, then lift out and slice.

Notes

These bars taste even better the next day after the flavors settle. If you cut them while still warm, use a sharp knife and wipe it between slices for cleaner squares.