Easy Rhubarb Crumble Bars Recipe
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Delicious easy rhubarb crumble bars are the perfect springtime treat made with tart rhubarb and wholesome oats.
Can you feel it? The air is warmer and new life is bursting through the ground. We have been anxiously anticipating you, spring! And with spring, comes my favorite, rhubarb season! Rhubarb custard dessert, blueberry rhubarb crisp, and strawberry rhubarb jam are among our favorites things to make. But at the top of the list are these easy rhubarb crumble bars.
Even though it looks like pink celery, fresh rhubarb makes the most delicious desserts. It’s so versatile and abundant, with many having a rhubarb plant growing in their backyard. If you don’t have any, just start asking around. I’m sure you have a neighbor or friend who is willing to divide some off for you. Otherwise, you can easily find some at a farmer’s market or in the produce section of most grocery stores. But don’t delay, it has a short season!
Because it was so easily accessible for me years ago, it was one of the very first things I started to preserve as a young mom, often making it into rhubarb jam. Then I discovered these bars! They are ridiculously easy to make, and my kids gobble them up, making them the perfect treat! Needless to say, I have been a fan of rhubarb for many years.
These bars can be enjoyed as a breakfast bar with their oatmeal bottom crust, making an easy breakfast when you’re on the go. Or you can add a scoop of ice cream over that crumble topping and you instantly have a great summer dessert. This is such a great recipe that whenever I bring these bars to a party, everyone asks for the recipe.
Rhubarb Crumble Ingredients
- Oatmeal
- Brown sugar
- All-purpose flour
- Baking soda
- Cold butter
Rhubarb Filling Ingredients
- Rhubarb stalks cut into 1/2-inch pieces
- Granulated sugar
- Arrowroot powder/cornstarch
- Water
- Vanilla extract
Easy Rhubarb Bar Instructions
- Preheat oven to 375 degrees. Remove the rhubarb leaves and throw them away. Wash and dice the rhubarb stalks into 1/2-inch pieces. Much like celery, the rhubarb stalks can be stringy. A sharp knife and cutting board are the best ways to cut. Once you have 3 cups, set aside.
Crumble Instructions
- Add oatmeal, brown sugar, all-purpose flour, baking soda, and cubed butter to a medium bowl.
- Using a pastry blender combine all of the dry ingredients into the butter.
- Press 2/3 of the crumble mixture in the bottom of the pan, forming the bottom layer of the bars. Set aside the rest of the crumb mixture.
Rhubarb Filling Instructions
- Add sliced rhubarb and white sugar to a medium saucepan. In a small bowl, combine the water and arrowroot powder until the arrowroot powder is dissolved. Add arrowroot water to the saucepan and cook on medium heat until the rhubarb is soft, and the liquid starts to thicken, stirring frequently. Add vanilla extract and continue to stir.
- When the rhubarb filling is thick and the rhubarb is soft, spread the rhubarb filling evenly over the pressed crumble mixture.
- Sprinkle the rest of the crumble mixture evenly over the top of the rhubarb filling.
- Bake bars in a preheated oven for 30 minutes or until the oatmeal crumb topping is starting to turn golden brown. Remove from oven and let cool on a wire rack.
Cut and enjoy these delicious rhubarb bars at your next picnic or simply for your loved ones at home!
Tips for Easy Rhubarb Bars
- Let these bars cool completely before cutting them.
- Enjoy bars with a scoop of vanilla ice cream for a delicious dessert.
- These bars are the best the day of with their crisp crust.
- Swap out half of the rhubarb with fresh, sweet strawberries to turn these into delicious strawberry rhubarb bars.
FAQ’s
What is Rhubarb?
Rhubarb is a perennial plant that thrives in cooler climates, doing best in zones 3-8. Consumed raw, it’s incredibly tart, often prepared with fruit or added sugar to help bring some balance. The color of rhubarb can range from bright red to green rhubarb with their taste being similar. The stalks are edible, but the leaves contain a toxic compound called oxalic acid, which can be harmful if ingested in large quantities.
Can I use Frozen Rhubarb?
Yes! Since rhubarb has such a short season, I always harvest as much of the rhubarb as possible before the plant decides to bolt. Whatever I don’t use up, I just slice up and put into the freezer. Then I have rhubarb ready to use year-round. To use from frozen, add the frozen rhubarb to the saucepan and continue to make as directed.
How Long do Rhubarb Crumble Bars Last?
These bars are best to be enjoyed the day that they’re prepared. They can be stored in an airtight container at room temperature for 3 days, with the crust slowly getting softer.
Can I Half the Recipe?
Yes! This recipe is easy to half and make using an 8X8 square pan. Adjust baking time to 20 minutes.
Easy Rhubarb Bars
Ingredients
Crumble Ingredients
- 1½ cups oatmeal
- 1½ cups brown sugar
- 1½ cups all-purpose flour
- ½ tsp baking soda
- 1 cup butter
Rhubarb Filling Ingredients
- 3 cups rhubarb, cut into ½-inch pieces
- 1½ cups granulated sugar
- ¼ cup water
- 2 tbsp corn starch or arrowroot powder
- 1 tsp vanilla extract
Instructions
- Preheat oven to 375 ℉.
- Wash and slice rhubarb into ½ pieces; set aside.
- In large mixing bowl, combine dry ingredients. Cut in butter. This will be your base layer and your crumble topping. Press ⅔ of the crumble mixture in an even layer in a 9 X 13 pan; set aside.
- In a small bowl, combine arrowroot powder and water until the arrowroot powder is dissolved. Add to saucepan with sliced rhubarb. Cook rhubarb and arrowroot mixture over medium heat until the rhubarb is soft, and the liquid becomes thicker, stirring continuously.
- Once the rhubarb is cooked, add vanilla extract and continue to stir. Pour cooked rhubarb filling over base layer. Take remaining crumble mixture and sprinkle over the top of the rhubarb filling layer.
- Bake at 375 ℉ for 30 minutes or until the oatmeal crumble is golden brown.
- Remove from oven and set on wire rack to cool.
- Cut into 24 bars when cool.
- Store bars in an airtight container at room temperature.
