For bars
3 very ripe (very soft) persimmons (1 1/4 lb total)
1 1/2 teaspoons fresh lemon juice
1 teaspoon baking soda
1 3/4 cups all-purpose flour
1 teaspoon salt
1 teaspoon cinnamon
1 teaspoon freshly grated nutmeg
1/4 teaspoon ground cloves
1 large egg
1 cup granulated sugar
1/2 cup vegetable oil
1 cup loosely packed dried pitted dates (5 oz), finely chopped
1 cup walnuts or pecans (3 1/2 oz), finely chopped
For glaze
1 cup confectioners sugar
2 tablespoons fresh lemon juice
1/8 teaspoon finely grated fresh lemon zest
 
Make bars:
Put oven rack in middle position and preheat oven to 350°F. Butter and flour a 15- by 10-inch shallow baking pan (1 inch deep), knocking out excess flour.Discard dried green or brown calyx (stem and leaves) from each persimmon, then force persimmons 1 at a time through a medium-mesh sieve into a bowl, using a rubber spatula to press hard on solids (discard solids). Transfer 1 cup purée to a small bowl (discard remainder) and stir in lemon juice and baking soda. (Mixture will become foamy, then jell slightly.)
Sift together flour, salt, and spices in another small bowl.
Whisk together egg, sugar, oil, and dates in a large bowl until just combined. Add flour mixture and persimmon mixture alternately in batches, beginning and ending with flour mixture and stirring until just combined. Stir in nuts.
Spread batter evenly in baking pan and bake until golden brown and a wooden pick or skewer inserted in center comes out clean, about 20 minutes. Cool completely in pan on a rack.
Glaze and cut bars:
Stir together all glaze ingredients until smooth, then spread over top of cooled cake. Cut crosswise into 8 strips, then lengthwise into fourths, for a total of 32 bars.

Active time: 30 min Start to finish: 1 1/2 hr (includes cooling)
Servings: Makes 32 bars