Rhubarb is one of the first harvests in many regions, ripening in early spring. This rhubarb crisp recipe is a delicious way to use it while it’s in season!
Originally published March 2023; this post has been updated.
Let’s start with what is rhubarb, exactly? A rhubarb plant is a long-lived perennial that grows on stalks — similar to celery, but much larger. The stalks range from pink to bright red.
The stalks of rhubarb are edible; the leaves are poisonous, as they contain dangerous levels of oxalic acid. You’d need to eat a lot to kill you, but small amounts can make a person sick.
The stalks are very tart, so you’ll often see rhubarb paired with strawberries to cut the tartness, and almost always in sweetened dishes like pie, cake, and jam — and this easy rhubarb crisp!
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Ingredients
Rhubarb — I use fresh rhubarb from the garden. It can often be found fresh at farmers markets during the spring months.
Flour — When I bake with all-purpose flour I opt for the unbleached version. Bleached flour is very white, but it’s also treated with bleaching agents that I don’t really need in my food.
Rolled oats — They’re not just for breakfast! Old fashioned rolled oats give this crisp a delicious flavor. Optionally, you can pulse half the oats in a blender to make them a bit more fine.
Sugar — Use your favorite brand of granulated cane sugar. I prefer organic.
Cornstarch — This is our thickener so the crisp isn’t watery.
Making Old Fashioned Rhubarb Crisp
Combine the crisp ingredients, except rhubarb, and press half of the mixture into the pan as a “crust.”
Top with the sliced rhubarb in an even layer.
Cook the syrup in a saucepan to dissolved all of the ingredients before pouring over the rhubarb.
Finally, top with the remaining crumb mixture.
Bake until brown and bubbly! Serve rhubarb crisp warm or at room temperature.
FAQs
Can I use frozen rhubarb instead of fresh?
I haven’t tested that in this recipe. In general though, you will want to thaw and drain the frozen rhubarb to remove excess moisture. Because of the freezing process, the rhubarb will have “shrunk” some with water loss, so you may need to add more to completely cover the crust. You’d also want to think about using less sugar syrup to combat excess moisture. Let me know in the comments if you work this out!
Can I make this crisp gluten-free?
Pick up a cup-for-cup gluten-free all-purpose flour and you can use that instead of wheat flour. Make sure your oats are certified gluten-free if it’s critical that this rhubarb recipe is gluten free.
Can I make crisp ahead?
I recommend baking the day you are serving. It tastes best fresh from the oven and still slightly warm. It will still be crisp later that day and likely the following day, but beyond that it will become soggy. Still delicious for up to 4 days when stored in the fridge, but the texture will have changed.
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Rhubarb Crisp
Ingredients
- 4 cups rhubarb chopped
- 1 ¼ cup all-purpose flour
- 1 cup rolled oats
- 1 ¼ cup brown sugar packed
- ½ cup melted butter
- 1 teaspoon ground cinnamon
For the sugar syrup:
- 1 cup granulated sugar
- 2 tablespoons cornstarch
- 1 cup cold water
- 1 teaspoon vanilla extract
Instructions
- Use a fork or pastry blender to combine the flour, oats, cinnamon, brown sugar, and melted butter in a medium bowl until it's crumbly.1 1/4 cup all-purpose flour, 1 cup rolled oats, 1 1/4 cup brown sugar, 1 teaspoon ground cinnamon, 1/2 cup melted butter
- Press one-half of the crumb mixture into a buttered 7"x11" or 8.5"x11" baking dish.
- Spread the rhubarb slices evenly over the pressed crumb mixture.4 cups rhubarb
- Make the sugar syrup: Whisk sugar, cornstarch, and water together in a small saucepan over medium-low heat. Cook until thick, clear, and bubbly, approximately 5-7 minutes.1 cup granulated sugar, 2 tablespoons cornstarch, 1 cup cold water
- Remove from heat and whisk in vanilla. Pour the sugar syrup evenly over rhubarb.1 teaspoon vanilla extract
- Crumble the remaining oat topping evenly over the rhubarb in the pan.
- Bake at 350 degrees until edges are bubbling and the crumb topping is browned, about 30-40 minutes.
Notes
- I used light brown sugar; dark brown sugar will provide a deeper molasses flavor if you prefer that.
- Serve this easy dessert with a dollop of whipped cream or a scoop of vanilla ice cream.
Nutrition
Love rhubarb? Be sure to try this rhubarb coffee cake, too!
More fruit desserts to try:
Originally published February 2021; this post has been updated.
Made this recipe I would cut back some on the water I like my bars crispier than this recipe produces. My bars got soggy in fridge
Thanks for the feedback.
Very good I did cut back a little on white sugar just the right amount of tartness
When I was a kid rhubarb was everywhere. Not anymore. But I was lucky and found some tonite at the grocery store. Lost my recipe,so I looked online and this is the one that I remember. I’ll make it tomorrow and I can’t wait!
I hope you loved it!
IT’s Rhubarb season! Easy and good way to use rhubarb! I made only half the recipe the first time. Tonight I’ll make the whole recipe for a party. Didn’t change a bit of the recipe.
I’m glad you liked it!
LOVED this recipe. I borrowed from a rhubarb tart recipe and added chopped raw pistachios to the crumb topping. Will definitely make again!
Great idea, sounds delicious!
I like this recipe but next time, I will double the amount of rhubarb
Sounds good, thank you!