Rhubarb White Chocolate Elderflower Tart (Printable)

Crisp tart with white chocolate elderflower custard and roasted rhubarb. A stunning spring dessert for celebrations.

# What You Need:

→ Tart Crust

01 - 1 3/4 cups all-purpose flour
02 - 7 tablespoons cold unsalted butter, cubed
03 - 1/4 cup powdered sugar
04 - 1 large egg yolk
05 - 1-2 tablespoons cold water
06 - Pinch of salt

→ Custard Filling

07 - 5 1/4 ounces white chocolate, finely chopped
08 - 1 cup heavy cream
09 - 3 tablespoons whole milk
10 - 1/4 cup elderflower cordial
11 - 3 large egg yolks
12 - 2 tablespoons granulated sugar
13 - 1 teaspoon vanilla extract

→ Rhubarb Topping

14 - 10 1/2 ounces rhubarb, trimmed and cut into 2-inch batons
15 - 1/4 cup granulated sugar
16 - Zest of 1 lemon
17 - 2 tablespoons elderflower cordial

# How-To Steps:

01 - In a food processor, pulse flour, butter, powdered sugar, and salt until mixture resembles breadcrumbs. Add egg yolk and 1 tablespoon cold water; pulse until dough begins to come together, adding more water as needed. Shape into a disk, wrap in plastic, and chill for 30 minutes.
02 - Roll out dough on a floured surface to fit a 9-inch tart tin. Press into tin and trim edges. Chill for 15 minutes. Preheat oven to 350°F. Line crust with parchment and baking beans; blind bake for 15 minutes. Remove beans and parchment, then bake 5-7 minutes more until golden. Cool completely.
03 - In a saucepan, heat cream and milk until steaming but not boiling. Whisk egg yolks, sugar, and vanilla in a bowl until pale. Slowly pour hot cream mixture into yolks while whisking constantly. Return mixture to saucepan over low heat, stirring until slightly thickened and it coats the back of a spoon. Remove from heat and stir in white chocolate and elderflower cordial until smooth.
04 - Pour custard into the cooled tart shell and refrigerate for at least 1 hour until completely set.
05 - Preheat oven to 375°F. Arrange rhubarb batons in a single layer in a baking dish. Sprinkle with sugar and lemon zest, then drizzle with elderflower cordial. Cover with foil and roast for 15 minutes. Remove foil and roast 5-8 minutes more until tender but not falling apart. Cool completely.
06 - Arrange cooled rhubarb over the set custard filling. Optionally, brush with additional elderflower cordial for shine. Chill until ready to serve.

# Expert Suggestions:

01 -
  • The custard sets perfectly firm so you can slice clean wedges without any wobble or mess.
  • Roasting the rhubarb keeps it tender but structured, so every bite has texture instead of mush.
  • You can make every component a day ahead and assemble just before guests arrive.
  • The floral notes from elderflower make this taste elegant without any fuss or exotic ingredients.
02 -
  • If you pour hot custard into a warm tart shell, the butter in the crust will melt and make everything soggy and greasy.
  • Tempering the egg yolks slowly is non-negotiable or you'll end up with sweet scrambled eggs instead of custard.
  • Roasting rhubarb covered first keeps it from drying out, but removing the foil at the end gives you those beautiful caramelized edges.
03 -
  • Freeze your tart shell for 10 minutes before blind baking to prevent shrinkage and slumping during the first bake.
  • Strain your custard through a fine sieve after adding the chocolate to catch any bits of cooked egg and guarantee a silky finish.
  • Taste your elderflower cordial first because some brands are much sweeter than others and you may want to adjust the sugar slightly.
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