Gluten-Free Apple Crumble Bars

These bars have three layers — a pressed oat and almond flour base, a lightly spiced cooked apple filling, and a crumble topping made from the same mixture as the base. The whole thing comes together in one bowl for the crust and crumble, and one small saucepan for the filling. They need a short chill after baking to firm up before slicing, which makes them a good make-ahead option.

Tart apples like Granny Smith hold their shape better during cooking and balance the sweetness of the maple syrup. Sweeter varieties like Honeycrisp work too but tend to soften more.

Ingredients

Crust and crumble (same mixture)

• 2 cups gluten-free rolled oats (certified gluten-free)
• 1 cup almond flour
• ⅓ cup brown sugar
• ½ teaspoon cinnamon
• ¼ teaspoon salt
• ½ cup melted coconut oil or butter

Apple filling

• 3 medium apples, peeled and diced into ¼-inch pieces (Granny Smith recommended)
• 2 tablespoons lemon juice
• 2 tablespoons maple syrup
• ½ teaspoon cinnamon
• ¼ teaspoon nutmeg
• 1 teaspoon cornstarch (optional, helps thicken the filling)

Instructions

Step 1 — Preheat and prep the pan Preheat oven to 350°F (175°C). Line an 8×8-inch baking pan with parchment paper, leaving some overhang on the sides — this makes lifting the bars out much easier.

Step 2 — Make the crust and crumble mixture In a large bowl, combine oats, almond flour, brown sugar, cinnamon, and salt. Add melted coconut oil or butter and mix with a fork until the mixture forms clumps. It should hold together when pressed but still look crumbly. Set aside one third of this mixture for the topping.

Step 3 — Bake the base Press the remaining two thirds of the mixture firmly and evenly into the prepared pan. Bake for 10 minutes until lightly set and fragrant. Remove from the oven and let cool slightly while you make the filling.

Step 4 — Cook the apple filling Combine diced apples, lemon juice, maple syrup, cinnamon, nutmeg, and cornstarch in a small saucepan over medium heat. Cook for 6–8 minutes, stirring occasionally, until the apples have softened slightly and the liquid has thickened. Remove from heat and let cool for a few minutes.

Step 5 — Assemble Spread the apple filling evenly over the baked base. Scatter the reserved crumble mixture over the top, spreading it to cover the filling without pressing it down — keeping it loose gives a better crumble texture after baking.

Step 6 — Bake Return to the oven and bake for 25–28 minutes until the topping is golden and the edges are bubbling. The center may look slightly soft — it will firm up as it cools.

Step 7 — Cool and chill Allow to cool completely at room temperature, then refrigerate for at least 30 minutes before slicing. The bars cut much more cleanly when fully chilled. Lift out using the parchment overhang and slice into 16 bars.

Tips

• Press the base firmly and evenly — a loose base absorbs too much moisture from the filling and becomes soggy
• Cut apples into small, even pieces so they cook through uniformly in the saucepan
• The cornstarch is optional but recommended — it thickens the filling enough that it doesn’t make the base wet during baking
• Don’t overmix the crumble once the oil is added — a fork is better than hands here, as the warmth of your hands can make the mixture too dense
• If the topping starts browning too quickly before the edges are bubbling, loosely tent with foil for the last few minutes

Variations

• Add nuts: Fold ½ cup chopped pecans or walnuts into the crumble mixture
• Add ginger: Include ½ teaspoon ground ginger or a small amount of crystallized ginger in the apple filling
• Add cranberries: Stir ¼ cup dried cranberries into the apple filling for tartness and color
• Pear version: Substitute pears for apples — use a firmer variety and reduce cook time slightly
• Vegan: Use coconut oil rather than butter — the recipe is otherwise already vegan
• Nut-free: Replace almond flour with sunflower seed flour or additional gluten-free oats ground finely in a food processor

Storage

• Refrigerator: up to 4 days in an airtight container, with parchment between layers to prevent sticking
• Freezer: wrap individual bars and freeze for up to 3 months — thaw overnight in the refrigerator
• Reheat briefly in the oven at 325°F or in the microwave for 30–40 seconds

Nutritional Information (per bar, approximate — makes 16 bars)

✓ Gluten-Free   ✓ Wheat-Free   ✓ Dairy-Free Option Available   ✓ Vegan Option Available

Recipe Details

• Cuisine: American / British-inspired
• Course: Dessert / Snack
• Skill Level: Beginner

Frequently Asked Questions

Why are my bars soggy? The two most common causes are a base that wasn’t pressed firmly enough, or too much liquid in the filling. Make sure to press the base down well before baking, dice the apples small so they release less liquid, and use the cornstarch in the filling to thicken the juices.

Why is my filling runny? Add the cornstarch to the filling mixture and cook until the liquid visibly thickens before spreading it onto the base. If it still looks thin, cook for another minute or two.

Can I make these vegan? Yes — use coconut oil instead of butter. Everything else in the recipe is already plant-based.

How do I get clean slices? Chill the bars fully in the refrigerator for at least 30 minutes before slicing. Use a sharp knife and wipe it clean between cuts.

Can I use a larger pan? Yes. A 9×13-inch pan works — spread the ingredients to fill the pan and check the bars a few minutes earlier since the layers will be thinner and bake faster.

Gluten-Free Apple Crumble Bars

Gluten-free apple crumble bars feature a soft, spiced apple center nestled between layers of golden oat crumble. These wheat-free bars are perfect for dessert, snacking, or cozy gatherings, delivering classic comfort with a gluten-free twist.

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Course: Gluten-Free Dessert

Cuisine: International

Calories: 190

Ingredients Equipment Method Notes

Ingredients

  

Crust & Crumble

• 2 cups gluten-free rolled oats
• 1 cup almond flour
• 1/2 cup coconut oil or butter melted
• 1/3 cup brown sugar
• 1/4 tsp salt
• 1/2 tsp cinnamon

Apple Filling

• 3 medium apples peeled and finely diced
• 2 tbsp lemon juice
• 2 tbsp maple syrup
• 1/2 tsp cinnamon
• 1/4 tsp nutmeg
• 1 tsp cornstarch optional for thickening

Equipment

• 8x8 inch baking pan
• Parchment paper
• Mixing bowls
• Measuring cups and spoons
• Small saucepan

Method

 

1. Preheat oven to 175°C (350°F). Line an 8x8 inch pan with parchment paper.
2. In medium bowl, mix oats, almond flour, sugar, salt, and cinnamon. Stir in melted oil to form a crumbly mixture.
3. Press 2/3 of the mixture into pan for base. Bake 10 minutes; remove from oven.
4. In small pan, cook diced apples, lemon juice, maple syrup, cinnamon, nutmeg, and cornstarch over medium heat until softened (6–8 min).
5. Spread apple filling over baked crust. Sprinkle remaining crumble evenly on top.
6. Bake 25–28 minutes until golden. Cool fully before slicing.

Notes

Use tart apples for best flavor.

Store bars in airtight container for up to 4 days. Freeze for longer storage.

Add chopped nuts to the crumble for extra crunch.