Lemon Rhubarb Bars

Lemon Rhubarb Bars are a bright and tangy dessert that combines the bold citrusy flavor of lemon with the tart sweetness of rhubarb, all layered over a buttery shortbread crust. With a silky, custard-like filling and a delicate crumb base, these bars are a fresh and elegant treat perfect for spring and summer.

Why You’ll Love This Recipe

These bars are a citrusy twist on the classic lemon bar—elevated with the punchy flavor of rhubarb. They’re easy to make, slice beautifully, and deliver just the right balance of tart and sweet. Whether you’re baking for a brunch, picnic, or just craving something refreshing and zesty, Lemon Rhubarb Bars are sure to brighten your day.

Ingredients

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

For the crust

• All-purpose flour
• Powdered sugar
• Salt
• Unsalted butter, cold and cubed

For the filling

• Fresh rhubarb, chopped
• Fresh lemon juice
• Lemon zest
• Granulated sugar
• Eggs
• All-purpose flour
• Cornstarch
• Vanilla extract (optional)

For garnish (optional)

• Powdered sugar

Directions

1. Preheat oven: Set oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper or lightly grease.
2. Make the crust: In a bowl, mix flour, powdered sugar, and salt. Cut in cold butter until the mixture resembles coarse crumbs. Press firmly into the bottom of the prepared pan.
3. Bake crust: Bake for 15–18 minutes, or until lightly golden. Remove from oven and set aside.
4. Prepare rhubarb: In a small saucepan, cook chopped rhubarb with a splash of water over medium heat until soft. Puree until smooth and let cool slightly.
5. Make the filling: In a bowl, whisk together eggs, sugar, lemon juice, lemon zest, flour, cornstarch, and vanilla extract. Stir in the rhubarb puree until well combined.
6. Bake the bars: Pour filling over the baked crust and return to the oven. Bake for 25–30 minutes, or until the center is set and does not jiggle.
7. Cool and chill: Let bars cool to room temperature, then refrigerate for at least 1 hour before slicing.
8. Dust and serve: Sprinkle with powdered sugar before serving, if desired.

Servings and timing

This recipe makes about 16–20 bars.
Prep time: 20 minutes
Bake time: 45–50 minutes total
Chill time: 1 hour
Total time: About 2 hours

Variations

• Add strawberries: Mix in strawberries with rhubarb for a fruity twist.
• Gluten-free: Use a gluten-free flour blend for both crust and filling.
• Extra lemony: Add more zest or a bit of lemon extract for a stronger citrus flavor.
• Nut crust: Substitute part of the flour in the crust with ground almonds for a nutty variation.
• Herbal notes: Add finely chopped fresh basil or thyme for a unique, aromatic spin.

Storage/reheating

Store Lemon Rhubarb Bars in an airtight container in the fridge for up to 5 days. For longer storage, freeze individual bars separated with parchment paper for up to 2 months. Thaw in the fridge before serving. These bars are best served chilled or at room temperature and do not require reheating.

FAQs

Can I use frozen rhubarb?

Yes, thaw and drain it well before cooking into a puree.

Do I need to peel rhubarb?

No, just trim the ends and chop. Peeling removes color and texture.

Can I make these bars ahead of time?

Absolutely—they need to chill before slicing, so they’re perfect for making a day ahead.

Can I skip the rhubarb?

You can, but then you’ll just have lemon bars. The rhubarb adds a unique tartness and color.

Why did my filling crack?

Overbaking can cause cracks. Pull the bars when the center is just set.

How do I get clean slices?

Chill the bars thoroughly and use a sharp knife wiped clean between cuts.

Can I use bottled lemon juice?

Fresh lemon juice is best for flavor, but bottled works in a pinch.

What if my rhubarb is very sour?

Taste the puree and adjust the sugar in the filling if needed to balance.

Can I reduce the sugar?

A small reduction is fine, but sugar also helps the texture and set of the custard.

What’s the best way to serve these?

Chilled with a light dusting of powdered sugar or topped with whipped cream for extra indulgence.

Conclusion

Lemon Rhubarb Bars are a fresh, tangy, and elegant dessert that highlights the best of spring flavors. With a creamy citrus filling and a buttery crust, they’re simple to make yet impressive enough to serve at any gathering. Whether you’re a rhubarb lover or just looking for something new, these bars are guaranteed to bring a pop of sunshine to your dessert table.

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