Best Rhubarb Custard Bars

These rhubarb bars are my favorite way to welcome spring every year. With a buttery shortbread crust and a creamy custard packed with tart rhubarb, each bar strikes just the right balance of sweet and tangy. They have become a staple at family gatherings and bake sales whenever rhubarb season arrives.

I first baked these when my neighbor brought over an armful of garden rhubarb and I needed a dessert for a weekend picnic. Since then my family begs for them every time the rhubarb comes in.

Ingredients

• All purpose flour: gives essential structure to both the crust and the creamy filling look for unbleached flour for the best flavor
• Powdered sugar: sweetens and helps yield a melt in your mouth crust be sure it is soft and free from lumps
• Cold butter: forms the base of the crust and makes it tender and flaky use high quality unsalted butter cut into cubes for best results
• Granulated sugar: sweetens the filling and balances the tart rhubarb
• Cornstarch: thickens the custard so the bars set up just right fresh cornstarch will ensure a smooth texture
• Salt: sharpens flavor and enhances sweetness use fine sea salt if you have it
• Eggs: provide richness and creamy texture make sure they are fresh and well beaten before adding
• Rhubarb: shines as the star ingredient choose crisp firm stalks with deep red or pink color and avoid leaves which are not edible

Step-by-Step Instructions

Prepare the Pan:

Grease an 8 by 8 inch baking dish with cooking spray and set it aside This ensures the bars release easily and keeps cleanup simple

Make the Shortbread Base:

In a large bowl whisk together the flour and powdered sugar until evenly combined Add the cold diced butter Use your fingers a fork or a pastry blender to cut the butter into the flour mixture just like making a classic pie crust The butter should be the size of small peas and when you press the dough together it should hold its shape

Form and Bake the Crust:

Pour the crumbly dough into the prepared baking dish Pat it firmly and evenly into the bottom of the dish so every bite has a perfect base Bake for 15 minutes until just beginning to set but not browned

Mix the Filling:

While the crust bakes whisk together the remaining flour granulated sugar cornstarch and salt in a large bowl Beat the eggs until well mixed and gently fold into the dry ingredients Add the chopped rhubarb Stir only until everything is just combined to prevent a tough filling

Assemble and Bake the Bars:

Pour the rhubarb mixture over the hot baked crust and smooth into an even layer Bake in the oven for 38 to 45 minutes until the center is set and does not jiggle when you move the pan

Cool and Chill:

Let the bars cool completely at room temperature then refrigerate for several hours Chilling helps the custard set and makes slicing clean bars much easier

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Rhubarb is truly my favorite spring ingredient since it reminds me of my grandmother’s patch in her backyard Each year I chop big bundles and freeze some but truly nothing beats tasting it fresh in these bars. Every time I bite into one of these creamy tart treats I am transported back to family gatherings around her kitchen table.

Storage Tips

After cooling cut the bars and layer them in an airtight container with parchment between layers They keep best in the refrigerator for up to four days For longer storage freeze whole bars in a tightly wrapped container and thaw overnight in the fridge for best texture

Ingredient Substitutions

If you do not have rhubarb try using an equal amount of chopped strawberries or raspberries for a different twist For a gluten free option swap the all purpose flour for a 1 to 1 gluten free blend Make the bars a little more tangy with lemon zest or tone down sharpness by swapping part of the rhubarb for thin sliced apples

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Serving Suggestions

Serve chilled slices straight from the fridge for a refreshing dessert Dust the tops lightly with powdered sugar just before serving Add a dollop of whipped cream or a scoop of vanilla ice cream to make it extra special for guests These bars are always the first thing gone at potlucks and brunches

A Quick History of Rhubarb Desserts

Rhubarb has been cooked in sweet treats for generations especially in parts of North America and Europe Most often found in pies and crisps it did not appear frequently in bar desserts until shortbread and sugar became pantry staples in home kitchens Rhubarb’s height of popularity in the spring means these bars have become a family tradition for many who wait all year to enjoy its tart bright flavor

Frequently Asked Questions

→ How do I keep the crust from getting soggy?

Pre-baking the shortbread crust for 15 minutes before adding the filling helps keep it crisp and prevents sogginess.

→ Can frozen rhubarb be used instead of fresh?

Yes, frozen rhubarb works well. Thaw and drain excess liquid before mixing into the custard to avoid runny bars.

→ Why is it important to let the bars cool before slicing?

Cooling allows the custard to set fully, ensuring clean cuts and well-shaped bars that hold together nicely.

→ What’s a good flavor variation for these bars?

Add the zest of a lemon or orange, or a dash of ground cinnamon, to give a new layer of flavor to the filling.

→ How should these bars be stored?

Keep the bars refrigerated for best texture and freshness. Chilled bars also slice more cleanly.