Make sure you have thoroughly dried the grated zucchini to keep it from being too wet/watery in the finished bread. I do this using paper towels and squeezing the zucchini shreds. (See video tutorial in the post.)
Preheat oven to 325°F. Lightly grease and flour a bread pan, 8.5x4.5-inch size.
In a bowl, whisk together the Greek yogurt, 2 tablespoons lemon zest, lemon extract, egg, coconut oil (measured when melted and cooled to room temperature), honey, and sugar. Stir in the zucchini.
In a separate bowl, stir together the oat flour (measured after blending), flour, baking soda, and salt. (How to make oat flour: pulse regular old-fashioned or quick oats in a blender or food processor until they resemble flour. Then measure and add to the bowl.)
Add the dry to the wet and mix until just combined. Overmixing will result in dense bread. Pour the mixture into the prepared pan.
Bake for 40–50 minutes or until a toothpick when inserted into the center comes out clean and the bread has begun to slightly pull away from the sides. If needed, tent some foil over the top to keep the top from over-browning.
Remove from the oven, allow to slightly cool, then invert onto a plate.
Glaze: Whisk together powdered sugar, 1/8 teaspoon lemon zest, and salt. Add 1 tablespoon lemon juice, until the glaze reaches the desired consistency. The glaze should be quite thick because it will melt over the hot bread.
Pour the glaze over the bread while still warm from the oven.
Video
Notes
Note 1: I use a 5.3-ounce container of lemon Greek yogurt by Chobani® or a lemon meringue flavor by Oikos®. If you can’t find lemon Greek yogurt, use vanilla or plain.Note 2: Lemon extract (found in the grocery store by the vanilla extract and other baking extracts) has a strong concentrated flavor important for the bread. I don’t recommend any substitutions.Storage: Keep Lemon Zucchini Bread at room temperature 2–3 days, then refrigerate, extending freshness another day. To freeze: cool, slice, wrap tightly, and freeze for up to 3 months. Thaw in fridge or at room temp.