Total Time: 1-1/2 hours
Hands On Time: 30 minutes
Yield: 12 to 15 squares
For the crust:
- 2 cups all-purpose flour
- 1 cup (2 sticks) unsalted butter, cut into 1/2-inch cubes, plus more for pan
- 1/3 cup confectioner’s sugar
Instructions:Preheat your oven to 375° and set a rack to the middle position. Butter an 11x16-inch jellyroll pan and line the bottom with parchment paper. (This recipe may also be made in a 9x13-inch baking dish; the squares will be thicker and fruitier, and they’ll require more baking time.)
Now make the crust: Put the flour, butter, and sugar in the bowl of a food processor and pulse until the mixture looks like coarse sand. Press into the prepared pan, working it into the corners and sides.
Transfer the pan to the oven, and bake until the crust is just beginning to brown, about 30 minutes. Halfway through baking, check the crust and press any puffed areas down with a fork.
For the topping:
- 4 large eggs, beaten
- 2 cups granulated sugar
- 1/2 cup all-purpose flour
- 3/4 teaspoon kosher or sea salt
- 3/4 teaspoon ground cardamom
- 4 cups thinly sliced rhubarb (cut crosswise into 1/4-inch-thick slices)
- Garnish: confectioner’s sugar
Instructions:While the crust is baking, prepare the topping: In a large bowl, whisk together the eggs, sugar, flour, salt, and cardamom. Then add the rhubarb and stir.
Spread the egg-and-rhubarb mixture evenly over the hot crust, return to the oven, and bake 30 to 35 minutes, until the top is set and beginning to brown at the edges. Turn on the broiler, if you like, to further brown and crisp the top, but don’t walk away! It can brown very quickly.
Cool the pan on a wire rack; when cool, sprinkle with confectioner’s sugar and cut into squares.