Lemon Rhubarb Bars

Lemon rhubarb bars are a zesty, tangy twist on classic lemon bars — combining the brightness of lemon with the tart bite of rhubarb for a dessert that’s refreshing, balanced, and incredibly satisfying. With a buttery shortbread crust and a smooth, citrusy rhubarb filling, these bars are the perfect treat for spring and summer gatherings.

Why You’ll Love This Recipe

These bars have the perfect balance of sweet and tart with a soft, custard-like filling and a crisp, buttery base. The rhubarb adds a subtle tartness that complements the lemon without overpowering it. They’re easy to make, can be made ahead, and are great for sharing — perfect for potlucks, picnics, or afternoon tea.

ingredients

this Recipe

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

For the crust:

• All-purpose flour
• Granulated sugar
• Salt
• Unsalted butter, melted

For the lemon rhubarb filling:

• Fresh rhubarb, finely chopped
• Granulated sugar
• Eggs
• Fresh lemon juice
• Lemon zest
• All-purpose flour
• Salt
• Optional: powdered sugar, for dusting

directions

1. Preheat oven to 350°F (175°C). Line a 9×13-inch baking dish with parchment paper, leaving some overhang for easy removal.
2. Make the crust: In a bowl, mix flour, sugar, and salt. Stir in melted butter until crumbly. Press evenly into the prepared pan.
3. Bake the crust for 15–18 minutes, until just lightly golden. Set aside to cool slightly.
4. Make the filling: In a saucepan, cook rhubarb with a few tablespoons of water over medium heat until softened, about 5–7 minutes. Let cool slightly, then blend into a purée.
5. In a large bowl, whisk together eggs, sugar, lemon juice, lemon zest, and flour until smooth. Stir in the rhubarb purée.
6. Pour the mixture over the slightly cooled crust and return to the oven.
7. Bake for 25–30 minutes, or until the center is set and just barely jiggles.
8. Let cool completely in the pan, then refrigerate for at least 1 hour before slicing.
9. Dust with powdered sugar before serving if desired.

Servings and timing

Makes 16 bars
Prep time: 20 minutes
Cook time: 45 minutes
Chill time: 1 hour
Total time: About 2 hours

Variations

• Add strawberries: Mix in a few strawberries with the rhubarb for a sweeter variation.
• Use a graham cracker crust: Swap the shortbread base for a graham crust for a different texture.
• Top with whipped cream: Serve with a dollop for extra indulgence.
• Make it gluten-free: Use a gluten-free 1:1 flour blend.
• Add coconut: Sprinkle shredded coconut on top before baking for a tropical touch.

storage/reheating

Store lemon rhubarb bars in an airtight container in the refrigerator for up to 5 days. For longer storage, freeze the bars in layers separated by parchment for up to 2 months. Thaw overnight in the refrigerator. These bars are best served chilled or at room temperature and do not require reheating.

FAQs

Can I use frozen rhubarb?

Yes, just thaw and drain it well before cooking to avoid excess liquid.

Do I need to cook the rhubarb first?

Yes, softening it helps it blend smoothly into the filling and improves texture.

Can I make this without a blender?

Yes, just mash the cooked rhubarb as finely as possible or strain it for a smoother texture.

Can I make these bars less sweet?

Yes, reduce the sugar slightly, but keep in mind the rhubarb and lemon are both tart.

How do I know when they’re done baking?

The filling should be set with just a slight jiggle in the center. It will firm up as it cools.

What kind of lemons work best?

Freshly squeezed lemon juice and zest from regular or Meyer lemons both work well.

Can I double the recipe?

Yes, use a larger baking sheet and increase baking time slightly.

Do I need to refrigerate the bars?

Yes, due to the custard-like filling, they should be stored chilled.

Can I make these ahead of time?

Definitely. They actually taste better after a few hours in the fridge.

What’s the best way to cut clean slices?

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

Conclusion

Lemon rhubarb bars are a bright, tangy treat that’s perfect for spring and summer. With their buttery crust and creamy, citrusy filling infused with tart rhubarb, they’re a delightful twist on a classic lemon bar. Easy to make and even easier to love, this dessert is sure to become a seasonal favorite.

Print