Preheat the oven to 350°F. Grease a 9- by 5-inch loaf pan.
As the oven heats, toast the nuts from 5 to 10 minutes until they are fragrant but not dark. Stir them after the first 5 minutes. When they have toasted, remove them immediately from the pan to stop them from toasting further.
In a small bowl, whisk together the flour, salt, baking soda, baking powder and cinnamon.
In a large bowl, beat the eggs until light. Add the sugar, mixing well. Stir in the mashed bananas, sourdough discard, melted coconut oil and vanilla.
Add the dry ingredients to the banana mixture and stir just until combined. Fold in the nuts and coconut.
Scrape the batter into the prepared pan and bake for 60 minutes. Insert a sharp knife into the middle of the loaf. If it doesn't come out clean, bake for another 10 minutes and test again for doneness. Cool the loaf in the pan for 10 minutes before inverting it onto a rack to cool completely. Run a knife along the edges of the pan to prevent the loaf from sticking.