Healthy Apple Crisp with Oats & Walnuts (Gluten-Free)

Juicy Fuji apples bake under a buttery, crumbly topping of oats, almond flour, and toasted walnuts. This healthy apple crisp is lightly sweetened, made with ghee, and gluten-free with certified gluten-free oats.

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Apple crisp served with a scoop of vanilla ice cream

Fall in my kitchen always starts with a big bag of apples on the counter. This healthy apple crisp is what I make with them. Juicy Fuji apples bake under a buttery, crumbly topping of oats, almond flour, and toasted walnuts. It’s lightly sweetened, made with ghee, and gluten-free with certified gluten-free oats.

I tested this recipe twice. The first time, the crumble was too thin and the filling was runny. So I used a little less fruit, made a lot more topping, and let it rest before serving. Now it has a generous, golden crumble and a jammy apple filling every time.

Apple crumble served in a plate with a scoop of vanilla ice cream

Why You’ll Love It

Buttery, crumbly topping. The walnuts get beautifully toasted, and the oats keep a nice bite.
Lightly sweetened. Sweet Fuji apples mean you need very little sugar.
No peeling. The skins stay on, which saves time and adds fiber.
Gluten-free. Just use certified gluten-free oats.
Simple pantry ingredients. There’s no special equipment, only two bowls and a baking dish.

Ingredient Notes

Ingredients for healthy apple crisp, including chopped Fuji apples, rolled oats, almond flour, walnuts, brown sugar, ghee, and spices

Fuji apples: I love Fuji here because they’re naturally sweet and hold their shape when baked. I leave the skin on for color, texture, and fiber. Honeycrisp or Gala also work well.
Cornstarch (cornflour): Just 1 tsp thickens the apple juices as they bake. In India and the UK, it’s called cornflour. In the US, “corn flour” can mean finely ground cornmeal, so look for “cornstarch” on the label.
Brown sugar: It melts into the topping and adds a gentle caramel flavor. White sugar or maple syrup work too (see the FAQ).
Rolled oats: Use certified gluten-free oats if you’re cooking for anyone who avoids gluten. Regular oats are often processed alongside wheat.
Almond flour: It adds a soft, nutty richness and keeps the topping gluten-free.
Walnuts: They toast in the oven and add the best nutty flavor. Pecans are a great swap.
Ghee: I use melted ghee for a toasty, buttery flavor. Melted butter works the same way.
Coconut oil: Use it melted, 1:1 in place of ghee. Refined coconut oil tastes neutral, while unrefined adds a light coconut flavor. Coconut oil is the swap that makes this recipe vegan.
Lime juice: It keeps the apples bright and balances the sweetness. Lemon juice works the same way.

Healthy apple crisp with a golden oat and walnut crumble topping in a baking dish

How to Make Healthy Apple Crisp

Step 1: Preheat and prep

Preheat your oven to 350°F (175°C). Lightly grease a 6″ x 7.5″ baking dish. Chop the apples into bite-size pieces, leaving the skin on. Roughly chop the walnuts and set them aside for the crumble topping.

Step 2: Make the filling

Add the apples to a bowl with the cornstarch, brown sugar, cinnamon, nutmeg, lime juice, and vanilla. Toss until no dry cornstarch is visible. Spread the apples evenly in the dish.

Apples tossed with cinnamon, brown sugar, and cornstarch in a mixing bowl

Step 3: Mix the dry topping

In another bowl, combine the oats, almond flour, walnuts, brown sugar, cinnamon, and salt.

Step 4: Add the ghee

Pour in the melted ghee and mix well. The topping will look loose and crumbly, like damp sand with chunks of walnut. That’s exactly right. In the oven, it turns golden, the walnuts toast, and the oats keep a nice bite.

Oat, almond flour, and walnut crumble topping mixed with melted ghee

💡 Tip: Prefer a crunchier topping with clusters? Add 1 more tbsp of melted ghee and 1 tbsp of maple syrup, then squeeze small handfuls together before topping.

Step 5: Top and bake

Pile all the topping evenly over the apples. It will look like a lot, and that’s exactly what you want. Bake at 350°F for 55 minutes, until the top is golden and the juices bubble in the center. If the top browns too fast, cover it loosely with foil.

💡 Tip: If your dish is very full, set it on a baking sheet to catch any juices that bubble over. Mine didn’t spill, but it’s an easy way to protect your oven.

Crumble topping piled over apple filling in a baking dish before baking

Step 6: Rest and serve

Let the crisp rest for 25 minutes. The juices thicken as it cools, so the filling turns jammy instead of runny.

Baked apple crisp with bubbling juices resting after coming out of the oven

Serving Suggestions

I served mine warm with a scoop of vanilla ice cream, and it’s hard to beat. Here are a few other ways to enjoy it:

A drizzle of salted caramel sauce
A spoonful of thick Greek yogurt or vanilla yogurt for a lighter treat
Whipped cream with a pinch of cinnamon
A splash of warm custard or heavy cream
A drizzle of maple syrup and a few extra toasted walnuts
A hot cup of masala chai on the side

Storage & Make-Ahead

Fridge: Cover and store for up to 4 days.
Reheat: Warm it at 350°F for 10 to 15 minutes to refresh the topping. The microwave works too, but the topping will be softer.
Freezer: Freeze baked and cooled crisp for up to 3 months. Thaw overnight in the fridge, then reheat in the oven.
Make ahead: Mix the crumble topping up to 3 days ahead and keep it in the fridge. Toss the apples and assemble just before baking so the topping doesn’t get soggy.

Apple Crisp FAQs

Do I need to peel the apples for apple crisp?

No. I leave the skin on Fuji apples. It softens as it bakes, adds color and fiber, and saves prep time. Peel them if you prefer a smoother filling.

Why is my apple crisp watery?

Apple crisp is always juicy straight from the oven. Bake it until the juices bubble in the center, not just around the edges, because cornstarch only thickens once the juice boils. Then let it rest for 25 minutes. The filling thickens a lot as it cools.

Can I use white sugar or maple syrup instead of brown sugar?

Yes, both work. White sugar swaps 1:1, but you lose brown sugar’s caramel flavor. Maple syrup also swaps 1:1, but because it’s a liquid, the topping bakes up softer and a bit chewier and browns faster. Check it after about 40 minutes and cover it with foil if needed.

Can I use cold butter instead of melted ghee?

Yes. Melted ghee or butter coats everything evenly and gives a light, crumbly topping with nicely toasted nuts. Cold butter, cut into small cubes and rubbed in with your fingertips, makes a slightly sandier, more classic streusel. Both work well.

Can I use coconut oil?

Yes, use melted coconut oil 1:1 in place of ghee. Refined coconut oil tastes neutral, while unrefined adds a gentle coconut flavor that goes well with apples.

Is this apple crisp vegan, gluten-free, or lactose-free?

Gluten-free: Yes, when you use certified gluten-free oats.
Vegan: Not as written, because ghee is a dairy product. Swap it for coconut oil and serve with dairy-free ice cream or coconut yogurt to make it vegan.
Lactose-free: Ghee has had almost all of its milk solids removed, so it contains only trace amounts of lactose. Many people with lactose intolerance handle it well, but it isn’t dairy-free. For a fully dairy-free crisp, use coconut oil.