Gluten-Free Cranberry Crumble Bars

Our easy gluten-free cranberry crumble bars recipe combines buttery oatmeal crumble and a jammy cranberry filling you’re going to love. Notes of vanilla, brown sugar, and orange zest give these yummy cranberry bars extra flavor!

When I made our Raspberry Crumble Bars this summer, I immediately knew I needed to make a fall version when cranberries were in season. It’s finally here, and this gluten-free cranberry bars recipe is every bit as good as I dreamed they’d be!

Two layers of buttery oatmeal crumble sandwich a layer of sweet, tart cranberry filling, with notes of fresh orange zest, vanilla, and brown sugar in every bite. YUM!

You’ll love that they taste like a cranberry pie, but without the fuss of a pie crust! They’re the perfect easy alternative to classic pie for Thanksgiving, and make a delicious dessert for the holiday season.

And, maybe best of all, this delicious cranberry crumb bars recipe starts with simple ingredients…

Start With Simple Ingredients

These easy cranberry crumble bars don’t call for any finicky ingredients. It’s just classic, simple ingredients like…

• Butter. Melted butter goes into the oatmeal crumble layers and adds delicious flavor. If you’re dairy-free, vegan butter sticks (like Earth Balance) should work just fine here!
• Sugar & Brown Sugar. A combination of granulated sugar and brown sugar gives the perfect balance of taste and texture to the oatmeal crumble topping, while granulated sugar helps tame the tart cranberries. 
• Gluten-Free Flour. We love and recommend King Arthur Measure-For-Measure Gluten-Free Flour blend. If you use another brand, make sure it contains xanthan gum. Weigh the flour for best results, or use the scoop and level method to avoid over packing flour into the measuring cup. I do not recommend coconut flour or almond flour for this recipe. 
• Gluten-Free Rolled Oats. I find that rolled oats give a better texture than quick oats here. Be sure to buy certified gluten-free rolled oats (old-fashioned oats) to avoid cross-contamination!
• Vanilla Extract. Always!
• Baking Soda. For tenderness and a slight puff.
• Salt. To balance the flavors in the oatmeal layers and the cranberry filling.
• Fresh Cranberries for the best flavor! If you only have frozen cranberries, they’ll also work here! See the notes in the recipe card below for tips.
• Cornstarch. The natural pectin in the cranberries helps thicken the filling, but we find adding a little cornstarch helps you get just the right texture!
• Fresh Orange Zest & Orange Juice. This double dose of orange brightens the cranberry flavor in these bars and makes them taste amazing!
• Maybe a Little Glaze. If you want, you can finish these gluten-free cranberry bars with a quick orange glaze, made from powdered sugar, orange juice, and a little vanilla.

How To Make Gluten-Free Cranberry Oatmeal Crumble Bars, Step By Step

As always, you can find the full recipe with ingredient amounts, detailed instructions, and tips in the recipe card below!

1. Preheat & Prep. To start, heat oven temperature to 350 degrees F. Line a metal 8×8 square baking pan with parchment paper.
2. Make The Crust Mixture. In a large bowl, combine cooled melted butter, brown sugar, granulated sugar, and vanilla. Stir to combine. Add gluten-free flour, gluten-free oats, baking soda, and salt and stir until clusters form and no dry patches remain. (The mixture will firm up as it sits!)
3. Divide The Crust Mixture. Set Aside 3/4 cup of the oatmeal crumb mixture for the top of the bars and pat the rest out into the bottom of the pan to form the bottom crust.
4. Make The Filling. In a medium saucepan, combine cranberries, sugar, cornstarch, orange zest, orange juice, and pinch of salt. Heat the mixture over medium heat, using the back of a spatula to gently crush the cranberries. Cook 15-20 minutes, stirring constantly, until the cranberry filling comes to a simmer and the sauce thickens. It should thicken enough to coat the back of your spatula. (It’ll look jam-like, like cranberry sauce.) Set filling aside to cool for 5 minutes.

5. Assemble The Bars. Pour the cranberry mixture over the bottom crust and spread into an even layer. (An offset spatula makes this easy!) Sprinkle the reserved 3/4 cup of the crumble mixture over the top of the cranberry layer. (It won’t completely cover the filling.)
6. Bake & Cool. Then, bake the bars in the preheated oven for 45-50 minutes, or until the crumb topping is golden brown and the jammy filling is bubbling around the edges. Cool 30 minutes on a wire rack, then transfer to the refrigerator to finish cooling completely. (This will make the bars easier to slice!)
7. Top With Glaze. If desired, combine powdered sugar, 1 Tablespoon milk, and vanilla extract in a liquid measuring cup or small bowl and whisk until smooth and just pourable, adding more milk if needed. Drizzle the glaze over the bars and let it set. (It should set quickly!)
8. Slice, Serve & Store. Use the parchment paper to lift the bars out of the pan and onto a cutting board. Carefully use a sharp knife to cut the bars into 12 rectangles and enjoy. Store leftover cranberry crumble bars in an airtight container in the refrigerator 3-4 days.