Preheat the oven to 350 degrees. Coat a loaf pan with coconut oil spray.
Whisk together the flour, baking powder, and salt until well combined.
Whisk the beaten eggs with the sugar and melted coconut oil until well combined. Add the buttermilk, lemon zest, and lemon juice, then whisk very well.
Add the zucchini and mix until evenly combined.
Slowly add the flour mixture to the egg mixture until just combined.
Pour into the loaf pan and gently tap it on the counter to remove any air bubbles.
Place into the oven and bake for 40-45 minutes or until a tester inserted into the center comes out clean.
Remove from the oven and let rest for 10 minutes, then remove the bread from the loaf pan and place it on a wire cooling rack until cooled completely.
Make the glaze by combining the powdered sugar, lemon juice, lemon zest, and milk until smooth, creamy, and at the desired consistency.
Place some parchment paper under the wire cooling rack with the zucchini bread on it.
Drizzle the lemon glaze over the top of the loaf until evenly coated.