How to Make It
Preheat oven to 325°F. Stir together flour, sugar, cinnamon, baking soda, and salt in a large bowl. Stir in persimmon pulp, oil, melted butter, and eggs until well incorporated; stir in walnuts.
Pour batter into a greased and floured 10-inch Bundt pan. Bake in preheated oven until a wooden pick inserted in center comes out clean, 55 minutes to 1 hour, 5 minutes. Transfer to a wire rack; let cool 10 minutes. Remove from pan; return cake to wire rack, and let cool completely, about 2 hours. Dust with powdered sugar.