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These irresistible Apple Crumble Bars are a simple way to get your apple dessert fix with minimal effort. A buttery oat layer topped with gooey apples and crumbly oat topping is the perfect cozy treat. Eat it as finger food or serve with a big scoop of vanilla ice cream!

Apple crumble bar propped up to see the layers among other apple crumble bars.

This recipe was originally published October 2016 and updated July 2022.

If there is a buttery, crumbly oat topping, then I am IN. These Apple Crumble Bars were inspired by my Mixed Berry Bars and Nutella Bars but with the perfect apple crisp twist!

If you love apple desserts, these apple crisp like bars are for you. So simple to make and you can even eat them with your hands. Although I highly advise a big scoop of vanilla ice cream with these bars!

Why You Will Love These Apple Crumble Bars:

They are so easy to make. When I say these apple crumble bars are simple to make, I mean easy with a capital E! Stir the crumble ingredients together, toss the apples in cinnamon and brown sugar and then assemble and bake. That is it!
Easy to make ahead of time. If you have a party you are preparing for, you can make these apple bars ahead of time and have them sliced and ready when the party starts. One less thing to do at the last minute!
An easy recipe for kids to help out with. This is my favorite recipe to make with my son. He loves helping cut the apples, stirring up all the crumble ingredients and putting it all together. Nothing complicated when making these, so it's always a hit!

Apple Crumble Bar Ingredients:

apples: I prefer gala or fuji--we always have them. I know granny smith is probably the most popular in apple crumble recipes, but I am not a fan. Use your favorite apple and you will be set! You can peel the apples or leave the skin on. I am too lazy usual to add another step so I just keep it on!
brown sugar: you will use brown sugar in the oat crumble and the apples. Light or dark brown sugar will work, I prefer light in this apple crisp bar recipe. If you are out of brown sugar, make your own!
cinnamon: you will need some for the apples and the crumble. I like to measure cinnamon with my heart, so sometimes I go a little heavy on it. It's just my FAVORITE.
corn starch: this will help thicken up the apple layer and make it more saucy than watery. You can use arrowroot powder instead if preferred.
lemon juice: I prefer freshly squeezed, but the stuff in the little bottles will work fine in this recipe as well.
quick oats: please use just quick cooking oats in this apple crumble bar recipe. Rolled or old fashioned oats won't hold up as well. If you only have rolled oats, pulse them a few times in the food processor or blender to break them down a bit. That should help. For gluten free, just make sure the oats say "gluten free" on the package.
flour: all purpose flour, spooned and leveled. You can sub a 1:1 gluten free all purpose with no issues to make these apple bars gluten free.
sea salt: table salt will work, sea salt is my preference.
baking powder: make sure it is fresh. It gives the crumble on top a light tender texture.
butter: I use unsalted, but salted will work just fine. You can lessen the salt by half.
vanilla: extract instead of imitation for the best flavor.

Oats, flour, cinnamon, butter and other ingredients on counter for recipe.

Step-By-Step Instructions:

Start by preheating the oven to 350°F.
Dice the apples, peeling first if preferred. Toss with the brown sugar, cinnamon, lemon juice, and corn starch. Set aside. (steps 1-2)
In a separate mixing bowl, combine the quick oats, flour, baking powder, and sea salt and whisk to combine. Add in the brown sugar and cinnamon and whisk. (steps 3-4)

Apples, brown sugar and cinnamon in mixing bowl and crumble mixture in separate bowl.

Add in the melted butter and vanilla and stir until all of the dry ingredients are incorporated. The mixture will be crumbly and moist, but not overly wet. (steps 5-6)
Begin to assemble the apple crumble bars. Line an 8 inch baking pan with parchment. Press ⅔ of the crumble mixture VERY WELL into the bottom of the pan. I mean, PRESS the mixture. Add the apples on top in an even layer, leaving out any of the liquid from the bottom of the bowl if there is any. (steps 7-8)

Butter mixed into crumble ingredients and then apple crumble bars beginning part of assembly.

Sprinkle the remaining crumble mixture over top and gently press into the apples. No need to do this firmly, just enough for the mixture to settle into the apples. (step 9)
Bake for about 30-35 minutes or until the top crumb layer is golden and crisp. Remove from the oven and allow to cool for at least an hour or so before slicing. For best results and easiest slicing, refrigerate for a couple hours before slicing. If you are going to eat the apple crumb bars with a fork, then slicing whenever is fine! (step 10)

Apple crumble bars before and after baking.

Recipe Tips:

These can be a bit messy when cutting. For easier and cleaner cut bars, refrigerate these apple crumble bars for several hours before cutting. This makes for much less of a mess!
If you want the apples layer to stand out a bit more, slice the apples and then lay them on top of each other versus dicing. Dicing the apples holds the bars together better because the crumble fills in all of the cracks. But if you want a distinct look in the apple layer, slice the apples thin and layer them.
Really press the bottom crumble layer into the pan. You want this to hold together well and if you don't really press it in, it will crumble apart--ha see what I did there?!
You can add other spices if preferred. A pinch of nutmeg, allspice or another cozy spice if you prefer. Even a touch of pumpkin spice if you are feeling really funky!

Apple crisp bars on parchment with apple sliced and cinnamon sticks.

Storing Your Apple Crumble Bars:

Store your apple bars in an air tight container for about 4-5 days at room temperature or you can refrigerate. If its super hot and humid where you live, the fridge is ideal as the crumble on top won't become soggy.

You can also freeze your apple crumble bars if preferred. I like to wrap individual slices in plastic and then store in a freezer safe container or in an added layer of foil. Freeze for up to 3 months, allowing to thaw before eating.

Reheating Your Bars:

If you want your apple bars crispy on top when eating, you can heat them up again easily. Broil for a few minutes or even place in an air fryer at 350°F for about 5 minutes.

These can just as well be served cold or at room temperature and are still amazing!