Preheat oven to 350 degrees. Grease a 9x5'' loft pan. Set aside two 4x6'' aluminum mini loaf pans.
In medium bowl, whisk together flour, salt, baking soda, baking powder, and cinnamon. Set aside.
In a large bowl, combine brown sugar, sugar, and melted butter. Use a study spatula to mix together. Add eggs and mix until incorporated.
Add about 1/3 of flour mixture to large bowl. Fold to combine.
Stir rum into persimmon puree. Add half of puree to mixing bowl. Mix, follow with another 1/3 of flour mixture. Mix, add remaining puree. Mix and adding remaining flour mixture. Stir together until there are no longer any dry streaks of flour.
Add pecans and fold until thoroughly distributed.
Transfer half of batter to prepared 9x5'' loaf pan. Divide remaining batter between two smaller loaf pans.
Bake 9x5'' loaf for 50-60 minutes until toothpick inserted in center of bread comes out clean. The smaller loaf should bake for about 40 minutes.
Let bread cool in pan for a couple of minutes before unmolding. Allow bread to come to room temperature before slicing.