The Bakery Chef™ comes up trumps with this one, taking care of both the tender, buttery pastry as well as the golden crumble topping. Rhubarb and apple are the fruity dynamic duo that take this tart to victory.
2Assemble the mixer with the glass bowl and scraper paddle. Add the flour, powdered sugar, ground almond and butter to the bowl. Slowly turn the mixer to FOLDING/KNEADING setting and mix until it resembles a sand like texture.
3Add the egg yolk and gradually add the ice water (if needed) until a dough forms.
4Remove the dough from the bowl and place it on a clean surface. Shape into a disk. Cover and refrigerate for 30 minutes.
5To make the crumble, place the sugar, almonds, cinnamon, oats and butter in a food processor and pulse until mixture starts to combine. Set aside.
6To make the filling, toss the rhubarb in the sugar and set aside.
7Roll the dough between sheets of parchment paper to form a 14-inch round. Remove the top sheet of paper and transfer (on the paper) to a baking sheet. Scatter half of the crumble mixture over the center of the dough round. Top with the apple and rhubarb mixture. Sprinkle with remaining crumble mixture.
8Bring the edges of the dough up over the filling, leaving top open. Brush the dough with the egg white and sprinkle with the demerara sugar.
9Bake for 30-45 minutes, or until golden.
10Serve the tart warm with vanilla pudding or ice cream.