
This rhubarb crisp is my favorite hint that summer’s just around the corner. Tangy bites of rhubarb hide under sweet, crunchy oats that fill the kitchen with the best smell. It’s the kind of no-fuss treat everyone crowds around after dinner.
Honestly this was the dessert I made non-stop when I first got into baking as a teenager, and my family always wanted me to bring it to cookouts. To this day, it’s still the one everyone fights over for that last scoop at a picnic.
Easy Ingredients
- Whole wheat or regular flour: Adds structure to your topping—go with whole wheat for a nuttier taste and more fiber, or classic all-purpose for old school vibes
- Rolled oats: Bring the signature chewy crunch to the topping, but grab old-fashioned oats because quick oats just go mushy
- Brown sugar: Lightly packed for deep, caramel-y flavor, make sure yours is soft for best results
- Cold butter (cubed): Keeps the topping flaky—real butter is best and cold chunks give you that bakery crumb
- Corn starch: Thickens the filling—pick gluten free if needed. When using fresh rhubarb, use a little less since it's not quite as juicy as frozen
- Granulated sugar: Balances rhubarb’s sour side—pure white works great for clean flavor
- Chopped rhubarb: Either frozen or fresh brings loads of tart flavor—look for firm, deep-red stalks and avoid limp ones
Effortless Step-by-Step
- Cool and serve:
- Take the pan out and let it sit about ten minutes so the filling thickens. Dig in while it’s still warm—top with vanilla ice cream if you’re feeling fancy.
- Assemble and bake:
- Spread all the topping over your rhubarb. Lightly pat but don’t press too hard—otherwise the top gets tough. Pop the pan on the center oven rack and bake around 35–40 minutes until you spot a golden crisp and juicy edges bubbling.
- Make the topping:
- Stir together the cold chunks of butter, oats, brown sugar, and flour in a clean bowl. Use your fingers, a pastry cutter, or a fork. Stop once it’s grainy with some pea-sized clumps left—that’s the trick for great crumbles.
- Mix the filling:
- Tip your chopped rhubarb into a bowl with sugar and corn starch. Mix until shiny and coated. If you’re using fresh rhubarb, back off on the corn starch or it turns gluey. Scrape it into your greased dish and spread out to the corners.
- Get your pan ready:
- Give your baking pan a light butter or oil swipe. Get those corners—nobody wants stuck-on fruit later.

I always think about my grandma when I see rhubarb. She let us grab fistfuls of red stalks from her garden every spring and the first crisp of the season was a big deal. She always left it in the oven until the top got extra crunchy—I do the same now and it never fails.
How to Store Leftovers
Wait for your crisp to cool off before covering it with foil or popping on a lid. Store in the fridge for up to three days. If you want the top to stay perfectly crisp, reheat in the oven—not the microwave.
Swaps and Mix-ins
If you need things gluten free, grab a GF flour mix. Rolled oats can also be certified gluten free. Allergic to nuts? No problem here. Short on rhubarb (or want a twist)? Toss in half apples or strawberries.
Fun Ways to Serve
This is great just warmed up or even chilled. Try spooning it over creamy yogurt for breakfast or add whipped cream for a bright finish at dessert. I love a bit of vanilla or honey ice cream right on top when it’s steaming from the oven.

Culture Corner
In both Europe and North America, rhubarb’s one of the first things to pop up in spring. Even though it’s usually tucked in desserts, it’s actually a veggie—not a fruit. Its sour bite makes it perfect for sweet treats like this!
Frequently Asked Questions
- → Can I use fresh or frozen rhubarb?
Yep, either works great! Fresh rhubarb needs just a little corn starch, but frozen needs the full amount to soak up all that juice.
- → What is the best way to create a crumbly topping?
Grab cold butter, cut it into little pieces, and use a fork or pastry tool to gently mix it into your dry stuff. That keeps it nice and chunky.
- → Can I substitute the flour?
Sure can. Go with all-purpose or whole wheat—just use what you like or have around.
- → Why should I let the crisp cool before serving?
Letting it cool makes the inside more set and holds together better. Plus, you won’t burn your mouth on hot filling.
- → How can I serve this dessert?
It’s really tasty warm. Try it with a scoop of vanilla ice cream or just whipped cream if you want.