If ever there was a treat that captured all the bright joy of spring, it’s got to be Rhubarb Custard Bars. With their buttery shortbread base, lusciously creamy custard layer, and pockets of tart, jewel-pink rhubarb, these bars are the perfect balance of sweet, tangy, and creamy. Whether you’re hosting a backyard brunch or just craving an afternoon pick-me-up, Rhubarb Custard Bars are the kind of dessert that draws friends and family around the table — and has everyone coming back for seconds.

Rhubarb Custard Bars Recipe - Recipe Image

Ingredients You’ll Need

The magic of Rhubarb Custard Bars is how just a handful of classic ingredients come together to make something truly special. Each component brings its own unique flavor and texture, ensuring bars that are perfectly balanced and absolutely irresistible.

All-purpose flour (2 cups + 1/4 cup): Essential for a sturdy yet tender crust, and also for thickening the creamy custard layer.
Granulated sugar (1/4 cup + 1 1/2 cups): Lends gentle sweetness to both the crust and the custard, offsetting rhubarb’s tang beautifully.
Cold unsalted butter (1 cup, cubed): Creates that melt-in-your-mouth, crumbly shortbread foundation every bar dessert dreams of.
Large eggs (3): Give the custard richness and help it set up just right for clean slicing.
Heavy cream (1 cup): Brings irresistibly silky texture to the custard and a touch of decadence.
Fresh rhubarb (4 cups, diced): The star ingredient! Bright, tart, and bursting with spring flavor.
Powdered sugar (optional, for dusting): Adds a pretty finish and an extra touch of sweetness to every bite.

How to Make Rhubarb Custard Bars

Step 1: Prep Your Oven and Pan

Start by preheating your oven to 350°F (175°C) so it’s nice and hot by the time you’re ready to bake. Lightly grease a 9×13-inch baking pan, making sure to get into the corners for easy bar removal later on. This simple step ensures your Rhubarb Custard Bars pop out looking picture-perfect.

Step 2: Mix and Press the Shortbread Crust

In a medium bowl, combine 2 cups of all-purpose flour with 1/4 cup granulated sugar. Add your cold, cubed butter and cut it in using a pastry cutter or your fingers until the mixture looks like coarse, sandy crumbs. Once you have your dough, press it firmly and evenly into the bottom of your greased pan. This is the foundation for all that delicious custard and rhubarb! Bake for 15 minutes, or until the crust is just turning golden around the edges.

Step 3: Prepare the Rhubarb Custard Filling

While your crust is baking, whisk together the eggs, 1 1/2 cups granulated sugar, 1 cup heavy cream, and 1/4 cup all-purpose flour in a large bowl. You want this mixture to be smooth, so give it a good stir. Once combined, fold in the diced rhubarb — those pretty pink cubes are about to become juicy, tangy pockets of flavor in your bars.

Step 4: Assemble and Bake

Carefully pour the custard and rhubarb mixture over your hot crust, spreading it gently to cover the base in an even layer. Slide the pan back in the oven and bake for 40 to 45 minutes. You’ll know your Rhubarb Custard Bars are done when the center is set and the top is just turning a light golden color. Your kitchen will smell absolutely heavenly!

Step 5: Cool, Slice, and Finish

Let the bars cool completely in the pan — this is the hardest part, but it makes for clean, tidy slices. Once cool, cut into bars. If you’d like, dust each one with a light shower of powdered sugar for a delicate, professional finish. Now, you’re ready to serve and delight.

How to Serve Rhubarb Custard Bars

Garnishes

These bars are lovely on their own, but a little extra flourish never hurts. A light dusting of powdered sugar adds a soft, snowy look and a hint of sweetness — plus, it makes your Rhubarb Custard Bars feel extra special. For a fresh touch, add a few sprigs of mint or a dollop of softly whipped cream on top of each bar.

Side Dishes

Pair these tangy-sweet bars with a cup of strong coffee for an afternoon treat, or serve with vanilla bean ice cream for a dreamy spring dessert. Because Rhubarb Custard Bars are rich and flavorful, they shine alongside lightly sweet or creamy sides — think fresh berries, lemon sorbet, or even plain Greek yogurt.

Creative Ways to Present

If you’re entertaining, arrange your Rhubarb Custard Bars on a tiered cake stand, alternating them with other colorful seasonal fruits for a stunning display. For picnics, wrap individual bars in parchment and tie with twine for easy, charming grab-and-go treats. You can even layer them in mason jars with whipped cream for a portable and playful trifle.

Make Ahead and Storage

Storing Leftovers

If you find yourself with leftovers (which is rare, trust me!), wrap your bars tightly or store them in an airtight container. Refrigerated, they’ll stay moist, creamy, and delicious for up to three days; the flavors meld even more with a little time spent chilling.

Freezing

Want to stash some Rhubarb Custard Bars for a future treat? Simply wrap cooled and sliced bars individually in plastic wrap, then pop them in an airtight freezer bag. They freeze beautifully for up to two months. Thaw overnight in the refrigerator and they’ll be just as tasty as the day you made them.

Reheating

If you like your bars just slightly warm, you can zap individual pieces in the microwave for 10-15 seconds. Or, place them on a baking sheet in a 300°F oven for a few minutes. Just be careful not to overheat, so the custard layer stays smooth and silky.

FAQs

Can I use frozen rhubarb instead of fresh?

Yes! If fresh rhubarb isn’t in season, you can use frozen. Thaw and drain the rhubarb well before adding it to the custard mixture, so your bars don’t end up watery.

Do Rhubarb Custard Bars need to be refrigerated?

Because the custard contains eggs and cream, it’s best to refrigerate these bars. They’ll stay fresh and firm, and they taste wonderful chilled.

Can I make these bars gluten-free?

Absolutely! Substitute a high-quality 1:1 gluten-free flour blend for the all-purpose flour. The bars will still turn out delicious and maintain their texture.

What if I want my bars less sweet?

If you prefer a tarter bar, feel free to cut back the sugar in the custard layer to 1 cup. The rhubarb’s natural tang will really shine through.

Is it possible to add other fruit to the recipe?

Definitely! Strawberries pair especially well with rhubarb. Try replacing 1 cup of rhubarb with diced fresh strawberries for a classic fruity combo.

Final Thoughts

If you’re looking to celebrate the vibrant flavors of spring or simply want a dessert that delights every time, don’t wait to try these Rhubarb Custard Bars. From their crisp base to their creamy, tangy top, there’s something a little magical about every bite. I can’t wait for you to bake a batch and share them with the people you love!

Rhubarb Custard Bars Recipe

5 Stars 4 Stars 3 Stars 2 Stars 1 Star

4.9 from 28 reviews

Author: Emma
Total Time: 1 hour 15 minutes
Yield: 12 bars 1x
Diet: Vegetarian

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Description

Indulge in the delightful combination of tangy rhubarb and creamy custard with these Rhubarb Custard Bars. A perfect dessert for any occasion, these bars are easy to make and a true crowd-pleaser.

Ingredients

Scale

For the Crust:

2 cups all-purpose flour
1/4 cup granulated sugar
1 cup cold unsalted butter, cubed

For the Custard Filling:

3 large eggs
1 1/2 cups granulated sugar
1 cup heavy cream
1/4 cup all-purpose flour
4 cups fresh rhubarb, diced

Powdered sugar for dusting (optional)

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Instructions

Preheat the Oven: Preheat the oven to 350°F (175°C) and grease a 9×13-inch baking pan.
Prepare the Crust: Combine 2 cups flour and 1/4 cup sugar. Cut in the cold butter until the mixture resembles coarse crumbs. Press into the pan and bake for 15 minutes.
Make the Custard: Whisk together eggs, sugar, cream, and flour. Stir in rhubarb. Pour over the hot crust and bake for 40–45 minutes.
Cool and Serve: Cool the bars in the pan, then cut into bars. Dust with powdered sugar if desired.