rhubarb-raspberry streusel tart with lavender whipped cream

One of my favorite moments each spring is discovering my rhubarb plants slowly making their way above ground. They are so faithful; no matter what the winter held for them, or how terribly I neglect them, they come back to me each and every spring. To reward them, I find plenty of ways to use their pretty pink stalks in the kitchen. This tart is always near the top of my ‘must-make-with-rhubarb’ list. I love pairing raspberries and rhubarb together, and while the filling is a bit tart, it balances nicely with the sweet streusel topping and rich buttery crust. The lavender whipped cream isn’t necessary, but adds another layer of flavor. It’s the perfect way to celebrate spring.
rhubarb-raspberry tart  | wit + delight
rhubarb-raspberry tart | wit + delight
rhubarb-raspberry tart | wit + delight
rhubarb-raspberry tart | wit + delight
Rhubarb-Raspberry Streusel Tart with Lavender Whipped Cream
loosely adapted from The Joy of Cooking: All About Pies & Tarts

Rhubarb releases a lot of liquid, so more cornstarch is needed in this tart. Frozen fruit also releases more liquid than fresh fruit, so if you want to use it, you will need to increase the cornstarch. However, if you use too much more cornstarch you will start to taste it, so I would recommend using fresh fruit here. The rhubarb and raspberries are a bit tart, but paired with the sweet streusel and rich crust, the flavors balance nicely.

pat-in-the-pan crust
2 cups flour
3/4 teaspoon salt
1 tablespoon sugar
12 tablespoons unsalted butter, soft
4-5 tablespoons heavy cream
egg wash (1 large egg mixed with 1 tablespoon water and a pinch of salt)

fruit filling
3 cups rhubarb, washed, trimmed and cut into 1-inch pieces
1 cup raspberries
1/2 cup white sugar
3 tablespoons cornstarch
1 tablespoon lemon juice
good pinch of salt

2/3 cup flour
2/3 cup rolled oats
1/3 cup white sugar
1/3 cup brown sugar
1/2 teaspoon cinnamon
1/4 teaspoon salt
5 tablespoons butter, melted

Lavender Whipped Cream
Lavender extract is not an easy-to-find item, but it does taste lovely in this whipped cream. I used this extract from Hatchery. If you want to omit it, replace it with 1/2 teaspoon of vanilla extract. Lavender has the potential to taste soapy, so just start with a few drops, and add more as desired.

1 cup heavy cream
2 tablespoons sugar
a few drops lavender extract, to taste

Add the cream, sugar, and lavender extract to a chilled mixer bowl. Beat on low speed until small bubbles form, about 30 seconds. Increase speed to medium and and continue beating, about 30 seconds. Increase speed to high and continue beating until cream is smooth, thick, and nearly double in volume, and 30 seconds.

For the crust:
Preheat the oven to 400. Grease a 10-inch tart pan with a removable bottom.

Combine the flour, salt, and sugar in a food processor, and pulse a few times to combine. Add the butter, and process until the mixture resembles coarse crumbs. Pour the heavy cream over the top of the flour mixture, and process again until the crumbs look damp and hold together when pinched. Transfer the dough to the tart pan and pat it evenly over the bottom and sides, pressing it firmly into the pan. Prick the bottom all over with a fork. Place a piece of parchment paper on top of the dough and fill it with baking beans (this is called blind baking, and you can read more about it here if you are unfamiliar with the term).

Place the tart pan on a half sheet pan and bake the tart crust for 18-22 minutes, or until the crust is golden brown. Remove the tart from the oven, and remove the parchment and beans from the crust. Brush the inside of the crust with the egg wash, and return it to the oven to bake until the wash sets, 1 or 2 minutes. Remove from the oven and let the tart crust cool.

For the filling:
Preheat (or lower oven temperature) to 350.

Combine the rhubarb, raspberries, sugar, cornstarch, lemon juice, and salt. Pour the filling evenly over the cooled tart crust. Sprinkle the streusel over the berries, and bake the tart until the streusel has browned and thick juices bubble near the center, 45-60 minutes. Let the tart cool completely on the rack, and serve the tart with lavender whipped cream.

For the streusel:
Combine the flour, oats, sugar, cinnamon, and salt together in a bowl, and pour the melted butter over the top. Mix the butter into the flour mixture and combine until it resembles coarse crumbs.

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