This fruit-filled dessert is a perfect way to use up produce.
Position a rack in the lower third of the oven and preheat the oven to 350˚F. Lightly grease a 9 × 13 inch glass or ceramic baking dish with butter or nonstick cooking spray.2.
Make the filling: In a medium saucepan, combine the apple juice concentrate, cardamom pods, star anise, cinnamon stick, vanilla bean, and salt. Set the pan over high heat and bring the liquid to a rapid boil. Boil for 1 minute. Remove the pan from the heat, cover the pan, and let steep for 30 minutes. Strain the juice, discarding the spices.3.
In a small bowl, whisk together 2 tablespoons of the spiced juice with the cornstarch until dissolved. Pour the rest of the juice back into saucepan and bring it back to a boil over medium-high heat. Whisk in the cornstarch mixture and continuing whisking until thickened and syrupy, about 1 minute. Remove the pan from the heat.4.
In a large bowl, combine the pears and apples. Pour in the lemon juice and toss, rubbing the lemon juice into the fruit pieces. Add the blackberries to the bowl. Pour the spiced apple syrup over the fruit and using a large flexible spatula, stir gently to combine. Scrape the fruit into the prepared pan, spreading it evenly.5.
Make the crisp topping: In another large bowl, whisk together the egg whites, honey, oil, vanilla extract, and salt until smooth. Add the oats and almond meal or ground almonds and stir until the oats are evenly moistened. Dump the topping onto the fruit and spread gently with your hands so that the crisp topping is in an even layer but not compacted. Sprinkle the top with turbinado sugar for extra sparkle and crunch, if you like.6.
Bake until the crisp is browned and the fruit is tender and bubbling, about 1 hour. Set the crisp to cool on a wire rack for at least 30 minutes before serving.