Ingredients
Scale
- For the Shortbread Crust:
- 1 1/2 cups all-purpose flour
- 1/2 cup granulated sugar
- 1/2 teaspoon salt
- 1 cup (2 sticks) unsalted butter, very cold and cut into cubes
- For the Rhubarb Layer:
- 3 cups chopped fresh rhubarb (about 1 pound), cut into 1/2-inch pieces
- 1/2 cup granulated sugar
- 2 tablespoons cornstarch
- 1 tablespoon fresh lemon juice
- For the Custard Filling:
- 4 large eggs
- 1 cup granulated sugar
- 1/4 cup all-purpose flour
- 1 cup whole milk
- 1 teaspoon pure vanilla extract
- Pinch of salt
- For Garnish (Optional):
- Powdered sugar for dusting
Instructions
- Preheat your oven to 375°F (190°C). Lightly grease a 9×13-inch baking pan and line it with parchment paper, leaving an overhang on the sides to easily lift out the bars later. This makes clean-up a breeze!
- Prepare the Shortbread Crust: In a large bowl, whisk together the flour, granulated sugar, and salt. Add the cold, cubed butter. Using a pastry blender, your fingertips, or a food processor, cut the butter into the dry ingredients until the mixture resembles coarse crumbs with some pea-sized pieces of butter remaining.
- Press the crumb mixture evenly into the bottom of the prepared baking pan. Bake for 15-18 minutes, or until the edges are lightly golden. Remove from oven and let cool slightly while you prepare the fillings.
- Prepare the Rhubarb Layer: In a medium bowl, combine the chopped rhubarb, 1/2 cup granulated sugar, cornstarch, and lemon juice. Toss gently until the rhubarb is evenly coated. Set aside.
- Prepare the Custard Filling: In another medium bowl, whisk together the eggs and 1 cup granulated sugar until light and frothy. Gradually whisk in the flour until no lumps remain. Then, slowly whisk in the milk, vanilla extract, and pinch of salt until the mixture is smooth and well combined.
- Assemble the Bars: Spread the prepared rhubarb mixture evenly over the pre-baked crust. Carefully pour the custard filling over the rhubarb layer, ensuring it covers all the fruit.
- Bake the Bars: Return the pan to the oven and bake for 30-35 minutes, or until the custard is set and the top is lightly golden brown. A slight jiggle in the center is okay, as it will continue to set as it cools.
- Cool and Serve: Remove the pan from the oven and place it on a wire rack to cool completely at room temperature. This is crucial for the bars to set properly! Once completely cool, transfer to the refrigerator and chill for at least 2 hours (or preferably overnight) before lifting from the pan using the parchment paper overhang. Cut into 16 squares. Dust with powdered sugar, if desired, just before serving.
Notes
For the best results and clean cuts, ensure the bars are thoroughly chilled before slicing. If your rhubarb is exceptionally tart, you can add an extra tablespoon or two of sugar to the rhubarb layer. These bars store beautifully in an airtight container in the refrigerator for up to 3-4 days. For an extra hint of warmth, consider adding a pinch of ground ginger or cardamom to the rhubarb mixture.
- Prep Time: 25 minutes
- Cook Time: 45 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 bar
- Calories: 320
- Sugar: 28g
- Sodium: 120mg
- Fat: 18g
- Saturated Fat: 10g
- Unsaturated Fat: 6g
- Trans Fat: 0g
- Carbohydrates: 45g
- Fiber: 1g
- Protein: 5g
- Cholesterol: 85mg