Rhubarb and Custard Crumble Bars (Printable Version)

Layered bars with tangy rhubarb, creamy custard, and buttery crumble topping. A delightful British springtime treat.

# Ingredient List:

→ Rhubarb Layer

01 - 14 oz fresh rhubarb, trimmed and chopped
02 - 5.3 oz granulated sugar
03 - 1 tablespoon fresh lemon juice
04 - 1 tablespoon cornstarch

→ Shortbread Base and Crumble

05 - 8.8 oz all-purpose flour
06 - 3.5 oz rolled oats
07 - 5.3 oz unsalted butter, cold and cubed
08 - 3.5 oz light brown sugar
09 - 1/2 teaspoon salt

→ Custard Layer

10 - 10 fl oz whole milk
11 - 2 large egg yolks
12 - 2.1 oz granulated sugar
13 - 2 tablespoons cornstarch
14 - 1 teaspoon vanilla extract

# Directions:

01 - Preheat oven to 350°F. Line a 9-inch square baking pan with parchment paper, leaving sufficient overhang for easy removal.
02 - Combine rhubarb, sugar, lemon juice, and cornstarch in a saucepan. Cook over medium heat, stirring frequently, until rhubarb softens and mixture thickens, approximately 8 to 10 minutes. Set aside to cool.
03 - In a large bowl, combine flour, oats, brown sugar, and salt. Rub in cold butter with your fingertips or pastry cutter until mixture resembles coarse breadcrumbs.
04 - Press two-thirds of the crumble mixture firmly into the bottom of the prepared pan to create an even base. Reserve remaining crumble for topping.
05 - Bake the base for 15 minutes until lightly golden. Remove from oven and allow to cool slightly.
06 - Heat milk in a saucepan until steaming but not boiling. In a separate bowl, whisk egg yolks, sugar, and cornstarch until smooth. Gradually pour hot milk into egg mixture while whisking constantly. Return mixture to saucepan and cook over medium heat, stirring continuously, until thickened, approximately 2 to 3 minutes. Remove from heat and stir in vanilla extract.
07 - Spread cooled rhubarb filling evenly over baked base. Pour custard layer over rhubarb.
08 - Sprinkle reserved crumble mixture evenly across the top layer.
09 - Bake for 30 minutes until crumble is golden and custard is just set.
10 - Cool completely in pan, then refrigerate for at least 2 hours before lifting out and cutting into 16 bars.

# Expert Advice:

01 -
  • Three distinct textures that somehow feel like one complete thought: buttery crumble, smooth custard, and jammy rhubarb.
  • The bars get better after a day in the fridge, so you can actually make them ahead for guests without stress.
  • British comfort food that tastes fancy enough for impressing people but honestly requires just basic kitchen skills.
02 -
  • Don't skip the chilling step, no matter how impatient you feel; the custard needs that time to set properly or your bars will fall apart when you cut them.
  • If your rhubarb layer seems too thick or too thin compared to the custard, that's completely fine and honestly doesn't matter as much as getting the flavors right.
03 -
  • If your custard looks slightly lumpy when you pour it out, strain it through a fine mesh sieve before spreading it; this takes thirty seconds and prevents little cooked egg bits from disrupting the smoothness.
  • A dusting of powdered sugar on top just before serving makes them look bakery-quality and hides any imperfect browning on the crumble.
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