Easy Rhubarb Crisp With Whole-Grain Oat Topping

This deliciously tart and sweet rhubarb crisp topped with a crunchy whole-grain oat topping is the ultimate springtime dessert… a scoop of creamy vanilla ice cream doesn’t hurt either! 

Every spring, I try to share a new rhubarb recipe as it’s great springtime treat, and where we live, rhubarb grows wild all over the place (so we can always get it for free).

We have a huge rhubarb plant in our vegetable garden, and while I do freeze some of the fruit for year-round baking, I also try to bake all sorts of easy rhubarb dessert recipes as much as possible every spring. 

Ingredients for Rhubarb Crisp

For the Rhubarb Filling

• 1.5 pounds rhubarb (about 4-5 cups, chopped)
• 1/4 c. granulated sugar
• 2 T. flour or cornstarch
• 1 T. lemon juice
• 1 t. vanilla extract

For the Topping

• 1/2 c. flour (use oat flour to keep it gluten-free)
• 1/2 c. oats (I prefer old-fashioned)
• 1/2 c. brown sugar
• 1/2 t. cinnamon
• 1/2 t. cardamom (optional)
• pinch of salt
• 4 T. very cold butter

In keeping with my dedication to eating whole grains, this recipe for Rhubarb Crisp is made with a delicious whole-grain flour and oat topping.

I use old-fashioned oats and white wheat berries that I grind myself in my Nutrimill grain mill. Of course, any store-bought flour will work just fine too! 

I also add a little bit of Cardamom — one of my new favorite spices — as I feel like it gives the topping an extra burst of flavor.

If you don’t already have Cardamom in the house, feel free to just use cinnamon instead. It’s not worth spending $7 on another bottle of spices if you won’t use it for anything else! 

How to Make Rhubarb Crisp

1. Prepare rhubarb by washing and dicing into bite-size pieces.

2. Place into a medium-size bowl with 1/4 c. sugar, 2 T. flour, lemon juice, and vanilla.

3. Stir and let sit in a colander over a bowl for a couple of hours (lots of juice will accumulate on the bottom of your bowl).

4. In a separate small bowl, mix flour, oats, brown sugar, cinnamon, cardamom, and salt.

5. Use a large-holed cheese grater to grate the cold butter into the oat mixture.

6. Mix butter into oat mixture (I like to use my hands to press the mixture together) until it becomes crumbly. Put in refrigerator until ready to bake.

When Ready to Bake:

7. Preheat oven to 375ºF.

8. Grease an 8″ x 8″ or 2.5-quart casserole dish.

9. Spoon rhubarb mixture into the dish (I use a slotted spoon so the liquid stays in the colander).

10. Sprinkle oat mixture over rhubarb.

11. Bake in preheated oven for 45 minutes or until topping is browned and rhubarb is bubbling up around the sides of the dish.

12. Serve warm with vanilla ice cream!

How to Prevent Soggy Rhubarb Crisp

As I mention in the recipe, I let my rhubarb “drain” for a bit to prevent the finished recipe from getting too soggy (a notorious down-side of baking with rhubarb).

To do this, I simply sprinkle a little sugar, flour, and lemon juice over the cut pieces of rhubarb and let them “marinate” in a bowl for a bit.

Then I put the rhubarb in a colander over the bowl and let all that liquid drip out (I eventually toss the liquid).  

This extra step will prevent too much juicy liquid from making the oat topping soggy.

Can you use frozen rhubarb?

You CAN use frozen fruit for this recipe — but again, you’d want to let it drain so your finished results aren’t soggy rhubarb soup! 

Rhubarb crisp is best served the day you bake it, but if you don’t mind a less crunchy topping, it will easily keep for a few days on your counter or in the refrigerator. 

In my opinion, the tart, tangy rhubarb, and sweet crunchy topping pair perfectly with creamy vanilla ice cream as the ultimate springtime dessert! 

What are your favorite ways to enjoy rhubarb? 

Visit my virtual recipe box for more simple, delicious, family-friendly recipes!