1 1/2 cups fresh Fuyu persimmon puree, or 3 Fuyu persimmons, peeled, seeded and mashed
Zest of 1 lemon
Juice of 1/2 lemon
1 cup sugar, plus more, for baking dish
Unsalted butter, for baking dish
10 slices (about 1 1/2 pounds) 1 1/2-inch-thick day-old or toasted brioche, cut into 1 1/2-inch pieces
1 teaspoon ground cinnamon
1/2 teaspoon freshly grated nutmeg
6 ounces white chocolate, coarsely chopped or chips
2 cups milk
3 large eggs
Preheat oven to 350 degrees. In a small saucepan, combine persimmon puree, lemon zest, lemon juice, and 1/2 cup sugar; simmer over low heat until sugar is dissolved.
Butter a 2-quart shallow baking dish, and sprinkle lightly with sugar. Place bread in baking dish; sprinkle with cinnamon and nutmeg.
In a medium saucepan, combine remaining 1/2 cup sugar, white chocolate, and milk; stir frequently over low heat. Remove from heat once chocolate melts.
Whisk eggs in a medium bowl. Slowly whisk warm milk mixture into eggs, being careful not to cook the eggs; stir in persimmon mixture. Pour mixture into baking dish, covering bread completely. Bake until filling sets, about 35 minutes.