1) Preheat oven to 350 degrees F. Add 1/2 cup unsalted butter to a small pot over medium-low heat. Once it melts, stir a bit and continue to cook until the melted butter foams and the foam breaks down. When it smells nutty and fragrant and you start to see tiny brown bits on the bottom of the pot, about 5-6 minutes, remove the pot from the heat.
2) Whisk together flour, salt, baking powder, and baking soda in a medium bowl. In a separate bowl, whisk together brown sugar, honey, browned sugar (cooled) and vanilla extract. It’s okay to add the browned bits to the mix also from the browned butter. Then stir wet stuff into the dry stuff.
3) Grate zucchini with skin on until you have two cups of packed zucchini (about 2 small zucchini). Then fold grated zucchini into the batter.
4) Lightly butter an 9×5 loaf pan and dust it lightly with flour. Then scoop the batter into the loaf pan. Bake the loaf for 55-60 minutes at 350 degrees until it’s nicely browned on the surface.
5) Let the loaf cool for 10 minutes or so and then remove the loaf from the pan. Slice and serve the loaf while warm. Once the loaf is completely cooled, it keeps great for a few days wrapped in plastic wrap.