Preheat the oven to 350°F (175°C). Grease and flour a 9×5-inch loaf pan.
In a medium bowl, whisk together the flour, baking soda, salt, cinnamon, and nutmeg. Set aside.
In a large bowl, cream the softened butter and granulated sugar together until light and fluffy, about 3-4 minutes.
Add the eggs one at a time, beating well after each addition, then stir in the vanilla extract.
Mix in the mashed bananas and crushed pineapple until combined.
Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, beginning and ending with the flour mixture. Stir just until combined; do not overmix.
Fold in the chopped pecans gently.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake in the preheated oven for 55 to 65 minutes, or until a toothpick inserted into the center comes out clean.
Remove the bread from the oven and allow it to cool in the pan for 10 minutes.
Transfer the bread to a wire rack to cool completely before slicing.