Preheat the oven to 350°F. Coat a 10-cup (2.5-liter) Bundt cake or tube pan with butter or nonstick cooking spray.
In a large bowl, sift together the flour, baking soda, cinnamon, nutmeg, and salt. Stir in the granulated sugar.
In a medium bowl or standing mixer, stir together the 3/4 cup melted butter, persimmon purée, eggs, and vanilla.
Add the flour mixture on low and stir just until everything is moistened; don't over mix. Stir in the chopped nuts, if desired.
Scrape the batter into the prepared pan and bake until a toothpick inserted into the cake comes out clean, about 1 hour. Remove from the oven and let cool completely.
Once the cake is cool, invert onto a serving plate. Dust with confectioners sugar and serve.