Preheat the oven to 400F and grease or use liners in a 6-jumbo muffin pan or a regular 12-muffin pan.
Use a cheese grater to grate the zucchini. Place the grated zucchini on a clean kitchen towel and squeeze out the excess moisture.
Make the batter:
In a bowl, combine the flour, sugar, poppy seeds, baking powder, baking soda, and salt.
In a large bowl, whisk the yogurt, melted coconut oil or butter, lemon juice and zest, and eggs.
Gradually, add the dry ingredients to wet ingredient bowl, and use a spatula to fold them in to combine. Once the mixture is cohesive, add the grated zucchini to the bowl and fold it into the batter.
Scoop the mixture into the prepared muffin pan, filling them almost to the top.
Bake:
Bake the jumbo muffins for 5 minutes at 400F. Lower the oven temperature to 350F and bake them for an additional 20 to 22 minutes. They are done when tops are golden and a toothpick comes out clean.
Bake regular-sized muffins for 5 minutes at 400F. Lower the oven temperature to 350F and bake them for an additional 15 to 17 minutes. They are done when tops are golden and a toothpick comes out clean.
Remove the muffins from the oven and let them cool down to room temperature before removing them from the pan.
Serve & store:
Serve slightly warm or at room temperature.
Store leftover muffins in an airtight container in the refrigerator for up to 4 days. Warm them up slightly in the microwave for 15 to 30 seconds if desired.