Preheat oven to 350°F and grease a 9x5-inch loaf pan.
In a bowl, whisk together flour, baking soda, baking powder, cinnamon, and salt.
In another bowl, beat eggs, coconut oil, sugar, and vanilla until smooth.
Stir grated zucchini into the wet mixture.
Slowly fold the dry ingredients into the wet mixture until combined.
Pour half the batter into the loaf pan, sprinkle with half the brown sugar-cinnamon mixture, then repeat with the remaining batter and topping.
Bake for 50–60 minutes or until a toothpick comes out clean.
Cool before slicing and enjoy the cinnamon-sugar crust.