Save The smell of elderflower always takes me back to late May mornings in my friend's garden, where we'd pick blossoms still wet with dew. One spring, she handed me a bottle of homemade cordial and challenged me to bake something worthy of it. I stood in my kitchen staring at a bunch of rhubarb, a bar of white chocolate, and that floral syrup, wondering if they'd even get along. They did more than get along—they became inseparable.
I first served this tart at a birthday lunch where half the guests were skeptical about rhubarb and the other half had never heard of elderflower. By the time I sliced into that golden crust and revealed the creamy custard beneath those pink-roasted batons, the table went quiet. Forks scraped plates clean, and someone asked if I'd consider making it again for her wedding. I did.
Ingredients
- All-purpose flour: The foundation of your tart shell, giving it structure without being too heavy or dense.
- Cold unsalted butter, cubed: Keeps the pastry flaky and tender; make sure it's straight from the fridge so it doesn't melt before baking.
- Powdered sugar: Sweetens the crust gently and helps it brown beautifully without graininess.
- Egg yolk: Binds the dough and adds richness, creating that melt-in-your-mouth texture.
- Cold water: Just enough to bring the dough together without making it sticky or tough.
- Salt: A small pinch balances the sweetness and sharpens all the other flavors.
- White chocolate, finely chopped: Choose good quality with real cocoa butter for a smooth, creamy custard that sets properly.
- Heavy cream: The luxurious base of your custard, giving it body and a silky mouthfeel.
- Whole milk: Lightens the custard just enough so it doesn't feel too rich or cloying.
- Elderflower cordial: The floral magic that makes this tart unforgettable; look for brands without artificial flavors.
- Egg yolks: Thicken the custard and give it that gorgeous pale yellow color.
- Granulated sugar: Sweetens the custard and helps the rhubarb release its juices during roasting.
- Vanilla extract: A warm undertone that supports the elderflower without overpowering it.
- Rhubarb, trimmed and cut into batons: Choose firm, bright stalks and cut them evenly so they roast at the same rate.
- Lemon zest: Brightens the rhubarb and adds a citrusy lift that cuts through the richness.
Instructions
- Make the Tart Shell:
- Pulse the flour, cold butter, powdered sugar, and salt in your food processor until it looks like coarse sand, then add the egg yolk and water until the dough just starts clumping together. Roll it out on a floured counter, press it gently into your tart tin, and let it chill so it holds its shape during baking.
- Blind Bake the Crust:
- Line the chilled pastry with parchment and fill it with baking beans or rice to keep it flat, then bake until the edges turn golden. Remove the beans and parchment, and bake a few minutes more until the base is crisp and lightly browned.
- Prepare the Custard:
- Heat the cream and milk until they're steaming, then slowly whisk them into your beaten egg yolks and sugar so you don't scramble the eggs. Cook gently on the stove, stirring constantly, until the custard thickens enough to coat the back of a spoon.
- Add the White Chocolate and Elderflower:
- Take the custard off the heat and stir in the chopped white chocolate and elderflower cordial until everything melts into a smooth, glossy mixture. Pour it into your cooled tart shell and let it chill in the fridge until firm.
- Roast the Rhubarb:
- Lay the rhubarb batons in a single layer in a baking dish, sprinkle with sugar, lemon zest, and elderflower cordial, then cover with foil and roast until tender but still holding their shape. Let them cool completely before arranging them on top of the set custard.
- Finish and Serve:
- Arrange the cooled rhubarb over the custard in whatever pattern makes you happy, brush with a little extra cordial if you want a glossy finish, and chill until you're ready to slice and serve.
Save There's something about slicing into this tart at a table full of people that feels like a small triumph. The crust shatters gently under the knife, the custard holds its shape, and the rhubarb glistens on top like jewels. Every time I make it, I'm reminded that some flavor combinations are worth taking a chance on, even when they sound a little unusual at first.
How to Store Leftovers
This tart keeps beautifully in the fridge for up to three days, covered loosely with plastic wrap or in an airtight container. The crust may soften slightly after the first day, but the flavors actually deepen and meld together, making leftover slices just as delicious. I've even eaten cold wedges straight from the fridge for breakfast, and I'm not ashamed to admit it.
Ingredient Swaps and Variations
If you can't find elderflower cordial, a light rose syrup or even a splash of limoncello works in a pinch, though the floral note won't be quite the same. Strawberries make a lovely substitute for rhubarb if you're baking outside of spring, and dark chocolate can replace white chocolate for a richer, less sweet custard. I've also added a handful of toasted pistachios on top for crunch, and it was a very good decision.
Serving Suggestions
This tart shines on its own, but a small dollop of lightly whipped cream or crème fraîche on the side never hurt anyone. It pairs beautifully with a chilled glass of Moscato, a sparkling elderflower drink, or even a strong cup of tea if you're serving it at an afternoon gathering. I like to bring it to the table whole and slice it in front of everyone, because the reaction is always worth it.
- Sprinkle with edible flowers like pansies or violas for an extra springtime touch.
- Serve with a drizzle of extra elderflower cordial around each slice for a restaurant-style presentation.
- Dust the edges lightly with powdered sugar just before serving if you want a softer, more rustic look.
Save This tart has become my go-to when I want to impress without pretending to be a pastry chef. It's elegant, a little unexpected, and tastes like spring no matter what month you bake it in.
Questions & Answers
- → Can I prepare this tart in advance?
Yes, this is an excellent make-ahead dessert. You can prepare the tart shell and custard a day ahead, then add the roasted rhubarb a few hours before serving. Store covered in the refrigerator.
- → What can I substitute for elderflower cordial?
If elderflower cordial is unavailable, you can use orange blossom water, rose water, or simply omit it and add an extra teaspoon of vanilla extract for a classic white chocolate flavor.
- → How do I prevent the rhubarb from becoming mushy?
Cut the rhubarb into uniform batons and watch carefully during roasting. Remove from the oven when tender but still holding its shape. Cooling completely before adding to the tart also helps maintain structure.
- → Can I use frozen rhubarb instead of fresh?
Fresh rhubarb works best for this tart as it maintains better texture. If using frozen, thaw completely and pat dry to remove excess moisture before roasting to prevent a watery topping.
- → What type of white chocolate should I use?
Choose high-quality white chocolate with at least 30% cocoa butter for the best flavor and smooth custard texture. Avoid white baking chips as they don't melt as smoothly.
- → How long will this tart keep?
The tart is best enjoyed within 2 days of assembly. Store covered in the refrigerator. The custard will stay fresh, though the rhubarb may release some juice over time.