Set the zucchini to drain in a sieve while you make the batter, you don't want all the water out of the zucchini just whatever drains out
Preheat the oven to 350°F
Lightly grease one 9x5 inch loaf pan
Melt the butter and let it cool, but do not let it solidify
Stir in the sugar
Beat in the eggs, vanilla, and cinnamon
Add the lightly drained zucchini to the mixture and stir to combine, set aside
In a separate bowl, mix together the flour, salt, baking powder, and baking soda
Add the buttermilk alternately with the flour mixture to the batter, stirring to combine
The batter will be lumpy. If there are still dry flour spots, stir a little longer
Bake for 55-65 minutes, don't open the oven door while it's baking, use the light to look at how it's doing in the oven if you need to
Start checking for doneness at 55 minutes, use a toothpick to check in several places it should come out with some crumbs but not wet batter
Cool completely, then store wrapped