Place the shredded zucchini in a sieve over a bowl to allow any excess moisture to drain away. Grate the lemon rind over top. Set aside while you get on with the rest of the recipe. (Sometimes there is a lot of moisture, sometimes none will come off at all, it just depends on the zucchini.) If the zucchini seems very moist, squeeze it out with a tea towel. I have never had to do this, but if you want a very dry muffin you may wish to.)
Preheat the oven to 350°F (170°C).
Line a 12 cup muffin pan with paper liners or spray with cooking spray.
In a large bowl, combine the flour, sugar, baking powder, ground ginger, chia seeds and salt. Set aside.
Beat the eggs in a medium bowl.
Add the zucchini and lemon rind, yogurt, olive oil and lemon extract (if using) to the eggs and mix together well.
Blend the wet ingredients into the dry ingredients until just mixed. Do not beat!
Using an ice cream scoop, fill the muffin cups half full.
Bake for 18 to 20 minutes or until golden. The tops of the muffins should spring back when touched lightly.
Cool in the pan for 5 minutes before removing to a wire rack to cool completely.