Best Rhubarb Crunch Recipe (Old-Fashioned Dessert)

Our Rhubarb Crunch recipe has the perfect balance of a sweet-tart rhubarb filling under the delightful crunch of a buttery crumble topping. This incredibly quick and easy recipe is a delicious way to enjoy fresh rhubarb flavor.

As soon as rhubarb season rolls around our old-fashioned rhubarb crunch recipe is one of the first recipes to hit the oven. We’ll show you how easy this sweet dessert recipe is to make.

What is Rhubarb?

A delicious Spring crop, rhubarb looks, feels, and crunches like a pink version of celery. Even though it’s mistaken as a fruit, it’s a vegetable. It can be eaten raw but it is very tart. Please note that the leaves are poisonous to humans and should never be eaten.

When baked with sweeteners, it makes delicious desserts while it is in season. Out of season, fresh rhubarb can be difficult to find in the grocery store but many of our rhubarb desserts can be adapted using frozen.

What is Rhubarb Crunch?

This is basically like a fruit crisp recipe, but the crunchy oat streusel topping gets crunchier. You may have heard a similar recipe called Rhubarb Crisp.

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Ingredients you’ll need for Rhubarb Crunch

• Fresh Rhubarb. Cleaned and diced rhubarb stalks.
• Granulated White Sugar. Balances out the tartness of the rhubarb.
• Cornstarch. Used for thickening.
• Water. Added to the cornstarch and sugar to make a syrup.
• Vanilla Extract.
• All-Purpose Flour. You can use gluten-free, one-for-one, all-purpose flour instead if needed.
• Rolled Oats. Old-fashioned rolled oats work best for the texture you want with this recipe.
• Brown Sugar. Dark or light brown sugar will work.
• Ground Cinnamon. I love Saigon cinnamon for a flavor punch.
• Butter. You could use a butter substitute as needed, but the flavor will be lacking.

How To Make Rhubarb Crunch

Please note, that the printable recipe card has the full list of ingredients, quantities, complete instructions, and nutritional information. The following is a quick overview of the recipe.

Step One. Get everything ready.

Go ahead and preheat your oven and spray your pan. Clean and dice the rhubarb and place it in the baking dish.

Step Two. Cook the thickener.

Add the water, sugar, and cornstarch to a saucepan. Whisk it to combine, and heat until thickened. Add the vanilla.

Step Three. Combine.

Pour the syrup over the rhubarb mixture into the baking dish.

Step Four. Make the Rhubarb Crunch topping.

Combine the topping ingredients, flour, oatmeal, brown sugar, and cinnamon. Add the melted butter and combine. Spread the crumble mixture over the top of the chopped rhubarb filling.

Step Five. Bake your Rhubarb Crisp.

Bake uncovered for 35 to 45 minutes.

What to Serve with this Recipe for Rhubarb Crunch

You can serve this tasty treat warm or cold, with whipped cream or a scoop of vanilla ice cream, or on its own. It works as a breakfast, snack, or an easy dessert.

Frequently Asked Questions

Can I use frozen rhubarb instead of fresh?

Yes, you can use frozen rhubarb. It’s best that you thaw rhubarb when baking with it. You’ll want to plan ahead because it can take several hours to thaw thoroughly. Place the frozen rhubarb in a colander set over a bowl at room temperature.

You can even thaw it overnight. Cover the top of the colander with plastic wrap so it doesn’t dry out and just dot any extra moisture from it using a paper towel. Don’t squeeze it. Too much moisture will make your rhubarb crisp runny.

How do I know the rhubarb crisp is done baking?

It will be hot and bubbly at the edges, and the top will be golden brown.

Can Rhubarb Crunch be made ahead of time?

Yes. Since it can be served warm or cold, you can make it a day ahead of time and refrigerate it.

How To Reheat & Store Rhubarb Crunch

Best way to store Rhubarb Crumble

Keep leftovers refrigerated. Cover the dish with aluminum foil, plastic wrap, or a lid, which should keep for three to five days. This will keep the juices from running and making the crunch soggy.

Can I freeze Rhubarb Crunch?

Yes. Freeze a whole dish or individual servings in airtight freezer-safe containers. Thaw to serve cold.

How to reheat

Reheat individual servings of Rhubarb Crunch in the microwave for fifteen to thirty seconds to serve it warm. Reheat an entire pan of the dish in the oven at 300ºF until hot and bubbly.

Hostess Tips for the Perfect Rhubarb Crunch

• Rhubarb doesn’t need to be peeled before you use it. Remove the leaves and I also remove the lowest part of the stem.
• The rhubarb needs to be chopped in consistent thicknesses so that the filling bakes at the same rate. We’ve found that 1/2-inch works well. Thinner and your filling could be mushy, thicker and it may be firmer.
• You can use more rhubarb in this recipe without adjusting the crumble amount. It’s important to cover the bottom of your baking dish.
• While we highly recommend Old-Fashioned Oats, you can use quick oats in a pinch. Just know that you won’t get the perfect crunch of this original recipe.

If you have plenty of rhubarb, you may enjoy one of our other favorite rhubarb recipes like Rhubarb Custard Pie, Rhubarb Cake, or this tasty Strawberry Rhubarb Bread. We even have a fantastic family recipe for Rhubarb Sauce that’s great for using up a lot of extra rhubarb. And, I adore this Lemon Rhubarb Bundt Cake.

I hope you enjoyed this delicious recipe as much as we do. Drop me a comment below, and don’t forget to give it a star rating. ⭐⭐⭐⭐⭐. Your comments and ratings help others decide if this recipe is for them too.

If you’re still looking for delicious fruit desserts with a delectable crunch, our apple crisp, peach crisp, and pear crisp recipes are very popular.

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