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