Gluten-Free Rhubarb Crisp

Gluten-free rhubarb crisp is a rustic, gorgeous dessert! A perfect mix of tart rhubarb, crunchy oats, spicy cinnamon, nutty buckwheat flour, and lots of butter.

This post first appeared May 15, 2020 and was last updated May 19, 2021.

Crisps are one of my favourite easy ways to use up fresh or frozen fruit, and this gluten-free rhubarb crisp is a knockout winner! It literally has every texture and flavour you could possibly want in a dessert — soft baked rhubarb, crunchy oat topping, tartness, sweetness, and a hint of spice and salt. Literally what more do you need?

Though we are not a gluten-free household, we do have gluten-intolerant family members. I also simply like the flavour of buckwheat flour so I always have it on hand and bake with it often.

This recipe calls for a total of 1 cup of sugar, which is kind of a lot for one square baking dish. If sugar is a concern, you can reduce the amount, however, keep in mind you do need some sweetness to balance the tart rhubarb. If you reduce the amount of sugar be prepared for your lips to pucker! Keep scrolling to the notes section below for more information and tips, as well as FAQs and substitutions.

Use the JUMP TO RECIPE button at the top of the post, or scroll to the bottom of the post, to see the full recipe card with ingredient measurements and instructions.

Ingredients

Step-By-Step Instructions

Preheat the oven to 350ºF (180ºC) and lightly grease an 8-inch (20-cm) square or round baking dish with butter.

In a large bowl, stir together the chopped rhubarb and lemon juice.

Mix together the sugar and cornstarch in a smaller bowl. Sprinkle the mixture over the rhubarb. Stir well to combine then set aside.

In a second larger bowl, combine the buckwheat flour, brown sugar, oats, cinnamon, and salt.

Mix everything together with your hands, breaking up any large chunks of brown sugar by rubbing them together with your fingers and thumbs.

Add the butter to the oat mixture.

Again with your hands, rub the butter into the buckwheat and oats using your fingers and thumbs. When all of the butter has been incorporated, with no bits of dry flour remaining in the bottom of the bowl, it’s ready.

Give the rhubarb a good stir then pour it into the prepared baking tin. Spread the rhubarb out in an even layer, then top it with the buckwheat-oat mixture.

Place the tin in the oven and bake the gluten-free rhubarb crisp for 40 to 45 minutes, or until the top is golden and the rhubarb is bubbling for a minimum of five minutes. Cool the crisp on wire rack for 15 minutes before serving warm, with ice cream or whipped cream.

Notes & Tips

If using fresh rhubarb for gluten-free rhubarb crisp, be sure to wash it first to rinse away dirt or tiny critters hanging on from the garden.

To use frozen rhubarb, there’s no need to thaw first. Simply proceed with the recipe as written.

If your stalks of rhubarb are huge, slice them in half lengthwise before chopping into chunks.

To keep this recipe gluten-free use certified gluten-free buckwheat flour and oats.

This gluten-free rhubarb crisp is evenly balanced with rhubarb filling and oat topping. If you like more fruit in your crisp, add up to 2 cups (300 g) more of chopped rhubarb. The baking time may change so watch for a golden top and bubbling fruit in the oven.

I mix the sugar and cornstarch in a small bowl before adding them to the rhubarb. This method ensures an even, lump-free coating, however, add them straight to the rhubarb without pre-mixing if you want.

Let the fruit in the gluten-free rhubarb crisp bubble in the oven for a minimum of five minutes to help ensure a properly thickened filling.

Substitutions

Quick oats can be substituted for rolled oats in gluten-free rhubarb crisp but won’t have the same texture.

I have substituted brown rice flour for buckwheat flour with great results.

If gluten-free isn’t a requirement you can substitute all-purpose flour or light spelt flour.

Make gluten-free rhubarb crisp dairy-free by substituting a good quality dairy-free margarine or solid coconut oil.

If you don’t have fresh lemon juice use bottled.

I chose cornstarch as the thickener for gluten-free rhubarb crisp, however, arrowroot powder or tapioca starch are also good options.

FAQs

More Rhubarb Recipes

Rhubarb Curd Creamy, tart, and sweet, use it on toast, ice cream, stir it into yogurt, spread it between cake layers, and so much more.

Maple Rhubarb Jam With Cardamom Lightly sweetened with maple syrup, this is a gorgeous small batch ruby red jam.

Rhubarb Fool With Cardamom Cream Layers of poached rhubarb and cream make for a show stopping dessert!

Rhubarb Scones With Fresh Ginger Rhubarb scones are a favourite spring treat! Spicy fresh ginger is a great match for the rich cream scone base and tart chopped rhubarb.

CHECK FOR STEP BY STEP PHOTOS ABOVE — Many of my recipes feature in-depth step-by-step images, plus useful tips to help you make the recipe perfectly the first time. If you make this recipe, please let me know how you made out in the comments below! I reply to all comments and will help troubleshoot if things don’t work out. I’d also grateful if you’d consider leaving a star rating while you’re here.

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Yield: 9 servings

Gluten-Free Rhubarb Crisp

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Gluten-free rhubarb crisp is a rustic, gorgeous dessert! A perfect mix of tart rhubarb, crunchy oats, spicy cinnamon, nutty buckwheat flour, and lots of butter.

Prep Time 20 minutes

Cook Time 40 minutes

Total Time 1 hour

Ingredients

For The Rhubarb Filling

• 4 cups (600 g) rhubarb, washed, chopped into ½-inch (1-¼ cm) chunks
• 2 teaspoons lemon juice
• ½ cup (100 g) sugar
• ¼ cup (30 g) cornstarch

For The Buckwheat Oat Topping

• ½ cup (80 g) buckwheat flour
• ½ cup (120 g) packed brown sugar
• ½ cup (45 g) rolled oats (also called large flake oats)
• 1 teaspoon ground cinnamon
• ⅛ teaspoon salt
• ½ cup (113 g) butter, room temperature

Instructions

1. Preheat the oven to 350ºF (180ºC) and lightly grease an 8-inch (20-cm) square or round baking dish with butter.
2. In a large bowl, stir together the chopped rhubarb and lemon juice.
3. Mix together the sugar and cornstarch in a smaller bowl. Sprinkle the mixture over the rhubarb. Stir well to combine then set aside.
4. In a second larger bowl, combine the buckwheat flour, brown sugar, oats, cinnamon, and salt. Mix everything together with your hands, breaking up large chunks of brown sugar by rubbing them together with your fingers and thumbs.
5. Add the butter to the oat mixture. Again with your hands, rub the butter into the buckwheat and oats using your fingers and thumbs. When all of the butter has been incorporated, with no bits of dry flour remaining in the bottom of the bowl, it’s ready.
6. Give the rhubarb a good stir then pour it into the prepared baking tin. Spread the rhubarb out in an even layer, then top it with the buckwheat mixture. Place the crisp in the oven and bake it for 40 to 45 minutes, or until the top is golden and the rhubarb is bubbling for a minimum of five minutes. Cool the crisp on wire rack for 15 minutes before serving warm, with ice cream or whipped cream.

Notes

If using fresh rhubarb for gluten-free rhubarb crisp, be sure to wash it first to rinse away dirt or tiny critters hanging on from the garden.

To use frozen rhubarb, there's no need to thaw first. Simply proceed with the recipe as written.

If your stalks of rhubarb are huge, slice them in half lengthwise before chopping into chunks.

To keep this recipe gluten-free use certified gluten-free buckwheat flour and oats.

This gluten-free rhubarb crisp is evenly balanced with rhubarb filling and oat topping. If you like more fruit in your crisp, add up to 2 cups (300 g) more of chopped rhubarb. The baking time may change so watch for a golden top and bubbling fruit in the oven.

I mix the sugar and cornstarch in a small bowl before adding them to the rhubarb. This method ensures an even, lump-free coating, however, add them straight to the rhubarb without pre-mixing if you want.

Let the fruit in the gluten-free rhubarb crisp bubble in the oven for a minimum of five minutes to help ensure a properly thickened filling.

Substitutions

Quick oats can be substituted for rolled oats in gluten-free rhubarb crisp but won't have the same texture.

I have substituted brown rice flour for buckwheat flour with great results.

If gluten-free isn't a requirement you can substitute all-purpose flour or light spelt flour.

Make gluten-free rhubarb crisp dairy-free by substituting a good quality dairy-free margarine or solid coconut oil.

If you don't have fresh lemon juice use bottled.

I chose cornstarch as the thickener for gluten-free rhubarb crisp, however, arrowroot powder or tapioca starch are also good options.

Nutrition Information:

Yield:

9

Serving Size:

1
Amount Per Serving: Calories: 35Total Fat: 0gSaturated Fat: 0gTrans Fat: 0gUnsaturated Fat: 0gCholesterol: 0mgSodium: 29mgCarbohydrates: 7gFiber: 1gSugar: 2gProtein: 1g

DISCLAIMER - NUTRITIONAL DATA IS PROVIDED BY A CALCULATOR AND IS A ROUGH ESTIMATION OF THE NUTRITIONAL INFORMATION IN THIS RECIPE.