Rhubarb Oat Bars

Rhubarb Oat Bars are a delicious and comforting dessert featuring a buttery oat crust, a tangy rhubarb filling, and a golden crumb topping. These bars strike a perfect balance between sweet and tart, making them ideal for spring and summer when rhubarb is at its peak. They’re great as a snack, breakfast bite, or an after-dinner treat.

Why You’ll Love This Recipe

• Seasonal and fresh: Perfect for using up fresh rhubarb from your garden or the market.
• Sweet and tangy balance: The tart rhubarb pairs beautifully with the sweet oat crumble.
• Easy to make: Simple ingredients and straightforward steps.
• Great for gatherings: Makes a crowd-pleasing dessert for potlucks and picnics.
• Freezer-friendly: These bars store well and can be made ahead.

Ingredients

this Recipe

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

• Fresh rhubarb
• Granulated sugar
• Cornstarch
• Water
• Lemon juice
• All-purpose flour
• Quick oats
• Brown sugar
• Salt
• Baking powder
• Butter

Directions

1. Make the rhubarb filling: In a saucepan over medium heat, combine chopped rhubarb, sugar, cornstarch, water, and lemon juice. Cook until the rhubarb is soft and the mixture thickens. Set aside to cool slightly.
2. Prepare the oat mixture: In a large bowl, mix flour, oats, brown sugar, salt, and baking powder. Stir in melted butter until the mixture is crumbly.
3. Assemble the bars: Preheat your oven to 350°F (175°C). Line a 9×9-inch baking dish with parchment paper. Press about two-thirds of the oat mixture into the bottom to form the crust.
4. Add the filling and topping: Spread the rhubarb filling evenly over the crust. Sprinkle the remaining oat mixture on top.
5. Bake: Bake for 50–60 minutes, or until the top is golden and the filling is bubbling around the edges. Cool completely before cutting into bars.

Servings and Timing

• Servings: About 16 bars
• Prep time: 20 minutes
• Cook time: 50–60 minutes
• Cooling time: At least 2 hours

Variations

• Strawberry Rhubarb Bars: Add chopped fresh strawberries to the rhubarb filling for a classic combo.
• Gluten-Free: Use a gluten-free flour blend and certified gluten-free oats.
• Nutty topping: Add chopped walnuts or almonds to the oat mixture for extra crunch.
• Vegan: Substitute plant-based butter for regular butter.

Storage/Reheating

• Room Temperature: Store in an airtight container for up to 2 days.
• Refrigerator: Keep in the fridge for up to 5–6 days.
• Freezer: Wrap bars individually and freeze for up to 3 months. Thaw overnight before serving.
• Reheating: Warm in a 350°F oven for 10–15 minutes to refresh the texture.

FAQs

How do I pick good rhubarb for baking?

Look for firm, crisp stalks with a deep red or pink color. Avoid any that are limp or have blemishes.

Can I use frozen rhubarb?

Yes, just thaw it completely and drain excess liquid before using in the filling.

Do I need to peel rhubarb?

No, peeling isn’t necessary. The skin softens during cooking and adds texture and color.

Can I make these bars ahead?

Yes, they’re perfect for making a day or two in advance and storing in the fridge.

What kind of oats should I use?

Quick oats are best for texture and binding, but rolled oats can work for a slightly chewier result.

Can I reduce the sugar?

Yes, you can slightly reduce the sugar, but keep enough to balance the tartness of the rhubarb.

What pan size should I use?

A 9×9-inch square pan works perfectly for this recipe.

How do I cut clean squares?

Let the bars cool completely, then use a sharp knife wiped clean between cuts.

Can I add spices?

Yes, a pinch of cinnamon or nutmeg in the oat mixture adds warmth and depth.

Are these bars good for breakfast?

Absolutely—they’re wholesome enough with oats and fruit, especially with a side of yogurt.

Conclusion

Rhubarb Oat Bars are a nostalgic and irresistible treat with their crumbly texture and tangy-sweet flavor. Whether you’re serving them at a brunch, packing them for a picnic, or sneaking one with your morning coffee, these bars are guaranteed to please. Make a batch while rhubarb is in season—you won’t regret it!

Print