Rhubarb Lemon Bars Recipe

Craving something that captures the essence of summer in a single bite? Look no further than these Rhubarb Lemon Bars—a vibrant twist on the classic lemon bar, with a pop of rhubarb’s tangy flair. They start with a buttery shortbread crust and are topped with a luscious, zesty lemon-rhubarb filling that’s tart, sweet, and addictively good.

Perfect for garden parties, picnic baskets, or a casual weekday dessert, these bars are easy to make and impossible to resist.

🍓 Why You’ll Love These Rhubarb Lemon Bars

• Bright & tangy flavor with the perfect balance of sweet and sour

• Buttery shortbread crust that melts in your mouth

• Colorful and seasonal, showcasing fresh rhubarb

• Make-ahead friendly for easy entertaining

• Simple ingredients and approachable steps for any skill level

🥣 Ingredients

For the Shortbread Crust:

• 1 cup (2 sticks) unsalted butter, softened

• ½ cup granulated sugar

• 2 cups all-purpose flour

• ¼ teaspoon salt

For the Rhubarb Lemon Filling:

• 2 cups fresh rhubarb, chopped

• ¾ cup fresh lemon juice (about 4 lemons)

• Zest of 2 lemons

• 4 large eggs

• 1 ½ cups granulated sugar

• ¼ cup all-purpose flour

• ¼ teaspoon salt

Optional for Serving:

• Powdered sugar, for dusting

• Thin lemon slices or edible flowers, for garnish

👩‍🍳 How to Make Rhubarb Lemon Bars

🔥 Step 1: Preheat the Oven

Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, leaving overhang on the sides for easy lifting.

🧈 Step 2: Make the Shortbread Crust

1. In a medium bowl, cream together the softened butter and sugar until light and fluffy.

2. Mix in the flour and salt until a soft dough forms.

3. Press the dough evenly into the bottom of the prepared pan.

4. Bake for 18–20 minutes, or until the edges are lightly golden.

5. Remove from oven and set aside to cool slightly.

🍋 Step 3: Prepare the Rhubarb Lemon Filling

1. While the crust bakes, place chopped rhubarb in a saucepan with ¼ cup water. Simmer over medium heat for 5–7 minutes until soft. Let cool slightly.

2. Use a blender or food processor to puree the rhubarb until smooth.

3. In a separate bowl, whisk together eggs, lemon juice, lemon zest, sugar, flour, and salt until smooth.

4. Stir in the rhubarb puree until well combined.

🧁 Step 4: Assemble and Bake Again

1. Pour the rhubarb-lemon mixture over the warm crust.

2. Bake for 25–30 minutes, or until the center is just set and no longer jiggly.

3. Let cool in the pan for at least 1 hour, then refrigerate for 2–3 hours (or overnight) for clean slicing.

✂️ Step 5: Slice and Serve

Lift the bars out using the parchment overhang. Slice into squares and dust with powdered sugar just before serving. Garnish with lemon zest or rhubarb ribbons for a fancy finish.

🍽 Serving Ideas

• Pair with a chilled glass of iced tea or lemonade

• Serve alongside whipped cream or vanilla yogurt

• Add a sprinkle of freeze-dried raspberry powder for color

📝 Baker’s Tips for Success

🌾 Use Fresh Rhubarb

Fresh rhubarb gives the best flavor and texture. If using frozen, thaw and drain well before cooking to avoid excess moisture.

🍋 Balance the Tartness

Taste your rhubarb puree before adding to the lemon mixture. If it’s very tart, you can increase the sugar slightly to compensate.

🔪 Chill Before Slicing

These bars firm up significantly in the fridge, making them easier to slice cleanly. Use a sharp knife and wipe it clean between cuts for the best presentation.

❄️ Storage & Make-Ahead

• Refrigerate: Store bars in an airtight container in the fridge for up to 5 days.

• Freeze: Wrap individual bars in plastic wrap and freeze for up to 3 months. Thaw in the fridge overnight before serving.

• Make-Ahead Tip: Bake the bars a day ahead and chill overnight for perfect texture and flavor.

💬 FAQs About Rhubarb Lemon Bars

❓ Can I use frozen rhubarb?

Yes, but thaw it fully and drain any excess liquid before cooking and pureeing. Too much water can make the filling loose or runny.

🥚 Are the bars supposed to be soft in the center?

Yes, they should be set but slightly soft and custard-like. Chilling after baking helps them firm up to the ideal consistency.

🍯 Can I adjust the sweetness?

Definitely. For a tarter bar, reduce the sugar by 1/4 cup. For sweeter results (especially with very sour rhubarb), add an extra tablespoon or two.

🌾 Can I make this gluten-free?

Yes. Use a gluten-free 1:1 flour blend for both the crust and filling. Almond flour may also work well in the crust.

🧈 Can I add other flavors?

Try adding 1/2 teaspoon of vanilla extract or a dash of ginger to the filling for a warm, spicy note.

🌞 Final Thoughts

These Rhubarb Lemon Bars are everything you want in a summer dessert—bright, zippy, and totally refreshing. They’re easy enough for weekday baking but elegant enough to impress guests at a garden brunch or bridal shower. Whether you’re a lemon bar lover or a rhubarb enthusiast, this hybrid recipe is bound to become your warm-weather favorite.

So grab a few lemons, some rhubarb, and get baking—you deserve a little slice of sunshine.