Few desserts celebrate spring as beautifully as Rhubarb Custard Bars. With their buttery shortbread crust, silky custard center, and sweet-tart rhubarb layer, these vibrant bars turn a humble garden vegetable into a bright, nostalgic treat. They’re the kind of dessert that reminds you of church potlucks, vintage cookbooks, and afternoons spent helping in the kitchen when rhubarb season arrived in full blush.
My earliest memory of Rhubarb Custard Bars comes from my great-aunt’s farmhouse kitchen, where rhubarb grew so wildly behind the garden fence that she baked with it nearly every week in spring. These bars were her specialty: tender, creamy, and perfectly balanced between tart and sweet. This recipe stays true to that old-fashioned charm while offering modern clarity, step-by-step guidance, and make-ahead tips to help you recreate them perfectly.
Below is a fully Rank Math–optimized guide complete with an easy recipe card, flavor pairings, troubleshooting, and FAQs, everything you need to master these timeless Rhubarb Custard Bars.
Table of Contents
Rhubarb Custard Bars Recipe Card
Prep Time: 20 minutes
Cook Time: 45–50 minutes
Total Time: 1 hour 10 minutes
Yield: 16 bars
Estimated Calories: ~255 per bar
Ingredients
Crust:
- 2 cups all-purpose flour
- 1/2 cup powdered sugar
- 1 cup cold unsalted butter, cubed
- Pinch fine sea salt
Custard Filling:
- 4 large eggs
- 1 1/2 cups granulated sugar
- 1/2 cup heavy cream or half-and-half
- 1/4 cup all-purpose flour
- 1 teaspoon vanilla extract
- 4 cups diced rhubarb
Optional Topping:
- Powdered sugar for dusting
- Whipped cream
Instructions
- Prepare the crust. Preheat the oven to 350°F (175°C). In a large bowl, combine flour, powdered sugar, and salt. Cut in the cold butter until the mixture resembles coarse crumbs.
- Press into the pan. Press crust mixture firmly into a greased 9×13-inch baking dish. Bake 12–15 minutes, or until lightly golden around the edges.
- Make the custard. Whisk eggs, granulated sugar, heavy cream, flour, and vanilla until smooth and silky.
- Add rhubarb. Fold in the diced rhubarb so it’s evenly coated in the custard.
- Pour over crust. Carefully pour the custard mixture onto the warm crust.
- Bake. Return to the oven and bake 30–35 minutes or until custard is set in the center and no longer jiggles.
- Cool & slice. Cool completely before slicing into bars. Dust with powdered sugar or add whipped cream to serve.
Substitutions & Dietary Swaps
- Gluten-Free: Use a 1:1 gluten-free flour blend for the crust and filling.
- Dairy-Free: Substitute coconut cream for heavy cream and vegan butter for crust.
- Lower Sugar: Reduce granulated sugar by 1/4 cup; rhubarb’s tartness will shine.
- No Rhubarb: Replace with tart berries like raspberries or strawberries.
- Citrus Twist: Add 1 teaspoon lemon zest for brightness.
Chef’s Pro Tips
- Dice rhubarb evenly for consistent baking and texture.
- Bake crust until lightly golden to avoid sogginess.
- Use room-temperature eggs for a smoother custard.
- Cool bars fully to allow custard to set properly.
- Dust with sugar just before serving, early dusting dissolves.
Make Ahead, Storage & Reheating
- Make Ahead: Bake and refrigerate up to 24 hours before serving.
- Storage: Store tightly covered in the fridge up to 4 days.
- Freezing: Freeze individually wrapped bars for up to 2 months; thaw in fridge.
- Reheating: Serve chilled or warm slightly in a low oven (200°F) for a softer texture.
Troubleshooting & Common Mistakes
- Custard too runny: Bars weren’t baked long enough; extend bake time by 5–7 minutes.
- Soggy crust: Crust was underbaked, aim for light golden edges.
- Rhubarb watery: Very fresh rhubarb releases juice; toss with 1 tsp flour before mixing.
- Bars falling apart: Needs more cooling time; chill 1–2 hours.
- Overly tart: Add an extra tablespoon of sugar or serve with whipped cream.
Flavor Pairings & Serving Suggestions
Rhubarb Custard Bars pair beautifully with light, creamy, or fruity flavors that balance their sweet-tart profile.
- Serve with vanilla bean ice cream.
- Add a drizzle of honey or citrus glaze.
- Top with toasted coconut or nuts for texture.
- Pair with hot tea or chilled lemonade.
Pairing Recipes From Our Website
Rhubarb Custard Bars
Ingredients
Equipment
Method
- Preheat the oven to 350°F (175°C). Grease a 9×13-inch baking pan.
- In a mixing bowl, combine flour and powdered sugar. Cut in the cold butter until the mixture resembles coarse crumbs.
- Press the crust mixture firmly into the bottom of the baking pan. Bake for 10 minutes.
- For the filling, whisk together eggs, sugar, and flour until smooth.
- Fold in the diced rhubarb, then pour the filling over the warm crust.
- Bake for 30–35 minutes, or until the custard is set and lightly golden around the edges.
- Allow to cool for at least 30 minutes before cutting into bars.
Notes
FAQs
Can I use frozen rhubarb?
Yes! thaw and pat dry before using to avoid excess moisture.
Do the bars need refrigeration?
Yes! the custard requires refrigeration for safety and texture.
Can I reduce the sugar?
Absolutely. Rhubarb is tart, but reducing sugar by 1/4 cup works well.
Why is my custard lumpy?
Eggs may have been too cold; whisk longer or start with room-temperature eggs.
Can I double the recipe?
Yes! use two 9×13 pans or one large sheet pan and adjust bake time slightly.
Can I add strawberries?
Yes! replace 1 cup rhubarb with diced strawberries for a sweeter variation.
Conclusion
With their buttery crust, creamy center, and bright rhubarb topping, Rhubarb Custard Bars capture everything we love about spring baking. These bars are easy, nostalgic, and crowd-pleasing, perfect for potlucks, brunches, holidays, or simply celebrating rhubarb season. Save the recipe and enjoy a taste of old-fashioned comfort in every slice.