Classic Zucchini Bread

½cup unsalted butter, plus more for greasing the pan
3 ½cups all-purpose flour
2teaspoons cinnamon
2teaspoons kosher salt
1 ¼teaspoons baking powder
1 ¼teaspoons baking soda
½teaspoon freshly grated nutmeg (or ¼ teaspoon ground nutmeg)
4large eggs
¾cup light brown sugar
¾cup sugar
¾cup canola oil
1 ½pounds zucchini, unpeeled and grated on a box grater (about 3 medium zucchini)
4tablespoons demerara or turbinado sugar (optional)

Heat oven to 350 degrees. Lightly grease 2 8-x4-inch loaf pans with softened butter and line with parchment paper.
Melt butter in a small pot over medium heat. Cook, swirling occasionally, until the butter starts to brown and smell like hazelnuts, 5 to 7 minutes. Use a whisk to scrape up any browned bits on the bottom of the pot; remove from heat and set aside.
Whisk together flour, cinnamon, salt, baking powder, baking soda and nutmeg in a large bowl.
Whisk together eggs, light brown sugar, sugar and canola oil in a medium bowl until no lumps remain and eggs are well blended.
Using your hands, squeeze out as much water as possible from the zucchini. Add zucchini and browned butter to the egg mixture, whisking to blend.
Make a well in the center of the dry ingredients and add the wet ingredients. Use a spatula to slowly incorporate until no dry spots remain.
Divide batter among prepared pans, smoothing the top. Sprinkle both with demerara sugar, if using, and place in oven. Bake, rotating once, until bread is golden brown on top, pulls away from the sides and springs back lightly when pressed at the top, 50 to 60 minutes.
Let cool completely on a wire rack before removing from loaf pans.