Apple, Rhubarb, Fennel, and Berry Strudel
For the vanilla cinnamon sugar
- 1 vanilla bean
- 3/4 cup granulated sugar
- 1/2 tsp. ground cinnamon
For the strudel
- 1-1/2 cups granulated sugar
- 1 lb. rhubarb, sliced on a diagonal 3/4-inch thick
- 1 small fennel bulb, halved, cored, and thinly sliced, preferably on a mandolin
- 1 lb. granny smith apples, very thinly sliced, preferably on a mandolin
- 1-1/2 cups raspberries
- 1/3 cup dried tart cherries, coarsely chopped
- 1/8 tsp. table salt
- 14 sheets of phyllo dough, (14 x 18-inch sheets), thawed according to package directions
- 1 cup lightly toasted coarse breadcrumbs
- 10 oz. (1-1/4 cups) butter, melted, more if necessary
- Confectioners’ sugar, for dusting
- Lightly sweetened whipped cream for serving
Make the vanilla cinnamon sugar
Cut the vanilla bean in half lengthwise and scrape out the seeds. Put the sugar in a small bowl, add the seeds and rub between your fingers to combine. Mix in the cinnamon, transfer to an air tight container, bury the empty vanilla bean pod in the sugar and set aside at room temperature overnight, or for up to 4 days before using.
Make the strudel
Put 3 cups of water in a 4-quart saucepan. Add the sugar and bring to a boil over high heat, stirring until the sugar has completely dissolved. Add the rhubarb, reduce to a low simmer, and poach, stirring occasionally until the rhubarb is barely tender, about 8 minutes. Remove the rhubarb using a slotted spoon and transfer to a medium bowl to cool. Add the fennel to the hot liquid and let steep, covered off the heat until slightly tender, about 10 minutes. Remove the fennel using a slotted spoon and transfer to a medium to a bowl to cool. Store the rhubarb and fennel refrigerated in separate covered containers until ready to use, or for up to 5 days.
Position a rack in the top third of the oven and heat to 375°F. Line 2 large rimmed baking sheets with parchment.
In a large bowl, toss together the rhubarb, fennel, apples, 1 cup of the raspberries, dried cherries, 1/4 cup of the cinnamon sugar, and the salt.
Lay out a damp kitchen towel and cover with a sheet of plastic wrap. Unroll the phyllo dough on top of the wrap, and immediately cover with a second sheet of plastic wrap and another damp towel. Evenly divide the breadcrumbs into two small bowls.
Remove 1 sheet of phyllo and place it on a work surface with a long edge facing you. Lightly brush the entire sheet with melted butter. Using one bowl of the breadcrumbs, sprinkle a light, even coating over the dough and place another sheet of phyllo on top. Repeat using a total of seven sheets of phyllo. It’s okay if you run out of breadcrumbs, just continue with a brushing of butter in-between each layer. Spread half of the filling lengthwise, on the top of the layered phyllo in a 3-inch wide strip, leaving a 2-inch border on the ends and a 1-inch border along the long edge closest to you. Sprinkle the filling with 2 Tbs. of the remaining cinnamon sugar, then drizzle with 2 Tbs. of the melted butter. Gently lift the 1-inch border of the phyllo over the filling and continue to roll to completely encase the filling. With the roll sitting seam side down, fold the ends underneath.
Transfer to one of the prepared baking sheets and gently shape and adjust the roll so that it is even and straight. Generously brush the roll with butter. Make 6 diagonal scores at even intervals in the top of the strudel. Repeat with the remaining phyllo, butter, breadcrumbs, filling, and sugar to create the second strudel.
Bake, rotating and swapping the pans halfway through, until golden brown, about 35 minutes. To serve, divide the remaining 1/2 cup of the raspberries among 12 dessert plates, slice the strudel along the scored marks, dust with confectioners’ sugar, and serve warm with the whipped cream.