Rhubarb Oat Bars

Rhubarb Oat Bars are a delightful sweet treat that perfectly balances tart rhubarb with a buttery oat crumble. With a crisp golden crust, a vibrant rhubarb filling, and a crumbly topping, these bars make an excellent snack, dessert, or even a special breakfast bite.

Why You’ll Love This Recipe

Rhubarb Oat Bars are simple to make, full of texture, and bursting with flavor. They’re a great way to use up fresh rhubarb during spring and summer months, and they store well, making them ideal for meal prep or sharing. The oats add a hearty bite, while the rhubarb keeps it fresh and tangy. These bars are perfect for potlucks, lunchboxes, or a cozy treat with coffee or tea.

ingredients

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

• Fresh rhubarb, chopped
• Granulated sugar
• Cornstarch
• Lemon juice
• All-purpose flour
• Rolled oats
• Brown sugar
• Baking soda
• Salt
• Unsalted butter, melted
• Vanilla extract

directions

1. Preheat oven to 350°F (175°C) and line an 8×8-inch baking dish with parchment paper.
2. In a saucepan, combine rhubarb, sugar, cornstarch, and lemon juice. Cook over medium heat until the mixture thickens and rhubarb softens, about 8-10 minutes. Set aside to cool slightly.
3. In a large bowl, mix flour, oats, brown sugar, baking soda, and salt.
4. Add melted butter and vanilla extract to the dry mixture and stir until crumbly.
5. Press about two-thirds of the oat mixture into the bottom of the prepared baking dish.
6. Spread the rhubarb filling evenly over the base.
7. Crumble the remaining oat mixture over the top of the rhubarb layer.
8. Bake for 30–35 minutes, or until the top is golden brown.
9. Allow to cool completely before cutting into bars.

Servings and timing

This recipe makes about 12 bars.
Prep time: 15 minutes
Cook time: 35 minutes
Cooling time: 30 minutes
Total time: 1 hour 20 minutes

Variations

• Add strawberries to the rhubarb mixture for a classic strawberry-rhubarb combo.
• Mix in chopped nuts like pecans or walnuts into the oat crumble for extra crunch.
• Use coconut sugar or maple syrup for a refined sugar-free version.
• Add a pinch of cinnamon or nutmeg to the crumble for warm spice notes.
• Make it gluten-free by using a gluten-free flour blend and certified gluten-free oats.

storage/reheating

Store Rhubarb Oat Bars in an airtight container at room temperature for up to 2 days or in the refrigerator for up to 5 days.
For longer storage, freeze them in a single layer and transfer to a sealed container or bag for up to 2 months. Thaw in the fridge overnight.
To reheat, warm briefly in the oven or microwave for a fresh-from-the-oven taste.

FAQs

Can I use frozen rhubarb?

Yes, frozen rhubarb works well. Thaw and drain it first to prevent excess moisture.

Do I need to peel rhubarb?

No, rhubarb does not need to be peeled. Just trim the ends and chop.

Can I reduce the sugar?

Yes, but keep in mind rhubarb is very tart. Adjust to taste, especially in the filling.

Are these bars suitable for breakfast?

Absolutely. They contain oats and fruit, making them a wholesome option for a sweet breakfast.

Can I make these vegan?

Yes, use plant-based butter to make the recipe fully vegan.

What kind of oats should I use?

Use rolled oats for the best texture. Quick oats can be used but will yield a softer bar.

How do I keep the crust from getting soggy?

Allow the bars to cool fully before cutting, and store them in a cool, dry place.

Can I double the recipe?

Yes, double the ingredients and use a 9×13-inch baking dish. Adjust the baking time as needed.

What if my rhubarb is very sour?

Taste the filling as it cooks and add a bit more sugar or a splash of vanilla to balance it out.

How do I know when the bars are done?

The top should be golden and crisp, and the filling should be bubbling slightly around the edges.

Conclusion

Rhubarb Oat Bars are a charming way to showcase rhubarb’s tart flavor with the comfort of a buttery oat crumble. Easy to bake and perfect for any time of day, these bars are a go-to treat when rhubarb is in season. Whether you’re making them for yourself or to share, they’re sure to please with their nostalgic and satisfying taste.

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