Rhubarb Tart with Brown Butter Streusel

I'm still working to find ways to use the huge stash of rhubarb I received a few weeks ago.  I hadn't previously eaten rhubarb, much less cooked or baked with it, so a whole new world opened up to me.  First, I made rhubarb jam, which I used in a bread pudding for Tuesdays with Dorie and subsequently to fill some homemade pop tarts.  But what to do next?  I've got my eye on a sorbet but until I clear some space in the freezer, that recipe is on hold.  I found a mini tart shell hiding in my freezer, something I'd tucked away after scaling back a recent TWD recipe, and decided to search for a recipe to fill it.  My only requirement: I didn't want another fruit competing with the rhubarb.  I've combined rhubarb with strawberries - classic and delicious - but this time I really wanted to let the rhubarb shine on its own.



The minute I saw this recipe my search was over.  I love all things streusel!  This one is even more fun than your typical streusel since it uses brown butter, which lends a wonderful nuttiness.  I modified the streusel to include oats instead of almonds since that's what I like but if you're an almond fan I think they'd be perfect here.  I quartered the recipe to fill my 4" tart shell and wound up with extra filling and streusel so I tossed them in a ramekin and baked it along with the tart.  Both were really, really good!  Surprisingly, I think I actually preferred the ramekin with just the rhubarb filling and the streusel topping over the tart with the crust.  The sweetness of the streusel was a fantastic complement to the tartness of the rhubarb.  I'd probably decrease the sugar in the filling by 1/4-1/2 cup next time because while the tartness of the rhubarb came through, I think the filling was a touch too sweet.  The tart is easy to throw together, especially if you prep the crust ahead of time and I can definitely see myself making this one again. 



I've included the crust portion of the tart from the recipe below but since I didn't use it, I can't really comment on it (for what it's worth, the reviews over at Epicurious are positive).  As I mentioned, my tart shell came from my freezer and was made using Dorie Greenspan's sweet tart dough.  It's a wonderful recipe, one of the few I've made that doesn't shrink like crazy in the oven.  You can find Dorie's recipe here on her site.

Rhubarb Tart with Brown Butter Streusel
adapted from Bon Appetit, January 2004 (via Epicurious.com)

Crust
1 1/2 cups all-purpose flour
3 tablespoons sugar
1/4 teaspoon salt
1/2 cup (1 stick) cold unsalted butter, cut into 1/2-inch cubes
1 large egg yolk
3 to 4 tablespoons chilled cream

Streusel
9 tablespoons unsalted butter, cut into 1/2-inch cubes
3/4 cup old-fashioned oats
3/4 cup packed light brown sugar
1 teaspoon ground cinnamon
3/4 cup all-purpose flour

Filling
5 cups 1/2-inch-thick slices rhubarb (from about 2 1/2 pounds)
1 1/4 cups sugar
1/2 cup all purpose flour
1 teaspoon lemon zest

To make the crust:  Blend flour, sugar, and salt in the bowl of a food processor for 5 seconds.  Pulsing, cut in the butter until coarse meal forms (the butter pieces should be pea-sized).  Add the egg yolk and 3 tablespoons of the cream.  Blend until moist clumps form, adding more cream if dough is dry. Gather dough into ball. Press enough dough into a 10-inch tart pan to make a 1/4-inch-thick crust. Pierce crust all over with fork. Chill at least 2 hours.

To make the streusel: Cook the butter in large skillet over medium heat until golden, stirring often, about 5 minutes.  Remove the pan from the heat then add the oats, brown sugar and cinnamon and stir to combine.  Add the flour and stir until moist clumps form.  Cool the streusel completely (the streusel can be made a day in advance and refrigerated).  

Preheat oven to 375 F.

To make the filling: Toss all ingredients in a bowl to blend. Let stand until the filling looks moist, stirring occasionally, about 15 minutes.

Bake the chilled crust until golden brown, pressing with back of a spoon if the crust bubbles, about 20 minutes. Remove from oven. Reduce oven temperature to 350°F.

Spoon the filling into the warm crust.  Crumble the streusel evenly over the filling.  Bake the tart until the filling is bubbling around the edges and the streusel is crisp and brown, about 1 hour.  (If the streusel or crust are browning too quickly, you can tent the tart with aluminum foil until the filling finishes baking.)  Cool tart on rack 30 minutes. Serve warm or at room temperature.