How to Make It
Preheat the oven to 350°. In a large bowl, whisk the flour with the brown sugar, oats, almonds, salt and nutmeg. Using your fingers, work in the butter until large crumbs begin to form. Press the streusel into small clumps and refrigerate until chilled, about 15 minutes.
Meanwhile, in a large ovenproof skillet, combine the cherries, granulated sugar, vinegar and the vanilla bean and seeds. Cook over moderate heat, stirring, until the juices are bubbling, 5 to 7 minutes. Stir in the grated pear and let cool completely; discard the vanilla bean.
Scatter the streusel evenly over the cherries. Bake for about 1 hour, until the topping is golden and the cherries are bubbling. Let cool slightly. Serve with vanilla ice cream.