Rhubarb Oat Bars

Rhubarb Oat Bars are a delightful dessert or snack that balances tart rhubarb with a sweet, buttery oat crumble. With a crisp base, juicy fruit center, and crumbly topping, these bars are as satisfying as they are easy to make.

Why You’ll Love This Recipe

These bars pack the perfect mix of sweet and tangy flavors, making them a favorite during rhubarb season. They’re simple to prepare with pantry staples, great for make-ahead baking, and perfect for spring and summer gatherings. Plus, they cut cleanly into squares for easy serving and storing.

ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

Crust and Topping:

• Old-fashioned rolled oats
• All-purpose flour
• Brown sugar
• Baking powder
• Salt
• Cinnamon (optional)
• Cold butter, cubed

Filling:

• Fresh or frozen rhubarb, chopped
• Granulated sugar
• Cornstarch or flour
• Lemon juice
• Vanilla extract (optional)

directions

1. Preheat oven to 350°F. Line an 8-inch square baking pan with parchment paper.
2. In a large bowl, mix oats, flour, brown sugar, baking powder, salt, and cinnamon. Cut in cold butter until mixture resembles coarse crumbs.
3. Reserve about 1 cup of the mixture for topping. Press the rest firmly into the prepared pan.
4. In another bowl, toss rhubarb with sugar, cornstarch, and lemon juice. Let sit for a few minutes, then spread evenly over the crust.
5. Sprinkle reserved oat mixture on top.
6. Bake for 45–50 minutes, or until the top is golden and the filling is bubbling.
7. Cool completely before slicing into bars.

Servings and timing

• Servings: 12–16 bars
• Prep time: 15–20 minutes
• Bake time: 45–50 minutes
• Cool time: At least 1 hour
• Total time: ~2 hours including cooling

Variations

• Mix in strawberries with rhubarb for added sweetness
• Add chopped nuts to the crumble topping
• Make it gluten-free by using certified gluten-free oats and flour substitute
• Add a touch of ground ginger or cardamom for spice
• Swap lemon juice with orange juice for a citrus twist

storage/reheating

• Store in an airtight container at room temperature for up to 3 days
• Refrigerate to extend shelf life by 2–3 more days
• Not ideal for freezing as texture may soften
• Reheat individual bars briefly in a microwave or enjoy chilled

FAQs

Can I use frozen rhubarb?

Yes, just thaw and drain it first to avoid excess moisture.

Do I need to peel rhubarb?

No, just trim the ends and chop. Peeling is not necessary.

Can I use quick oats instead of rolled oats?

Yes, but the texture will be softer.

How do I know when it’s done baking?

The top should be golden and the filling bubbling at the edges.

Can I make this recipe vegan?

Yes—use plant-based butter.

Should I pre-cook the rhubarb?

No, it cooks down perfectly in the oven.

How do I make these less sweet?

Reduce the sugar in both the filling and crust slightly to taste.

Can I double the recipe?

Absolutely—use a 9×13 pan and adjust the bake time slightly.

What’s the best way to cut clean bars?

Cool completely, refrigerate if needed, and use a sharp knife wiped clean between cuts.

Can I add other fruits?

Yes! Strawberries, raspberries, or apples pair well with rhubarb.

Conclusion

Rhubarb Oat Bars are a delicious and simple way to enjoy the fresh, tart flavor of rhubarb. Whether for dessert, a picnic, or a sweet snack, these crumbly, fruity bars will quickly become a seasonal favorite. Make a batch and enjoy the taste of spring in every bite.

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