01 - Preheat the oven to 350°F. Lightly grease a baking dish large enough to hold the persimmon halves in a single layer.
02 - Arrange the persimmon halves, cut side up, in the prepared baking dish.
03 - In a small bowl, mix 2 tablespoons brown sugar, cinnamon, ginger, nutmeg, and lemon juice. Spoon this mixture evenly over the persimmons.
04 - In a medium bowl, combine oats, flour, 1/4 cup brown sugar, salt, and nuts. Add the cold butter and rub with your fingertips until the mixture resembles coarse crumbs.
05 - Sprinkle the oat crumble generously over the persimmons.
06 - Bake for 30-35 minutes, or until the topping is golden brown and the persimmons are soft and bubbling.
07 - Allow to cool slightly before serving. Serve warm, optionally with a scoop of vanilla ice cream or Greek yogurt.