Preheat oven to 325°F (160°C). Line a cookie tray with parchment paper. Slightly oil the paper with coconut oil or oil spray. Set aside.
Trim zucchini ends, keep their skin on and grated finely with a hand grater or food processor.
Place the grated zucchini in the center of a towel, wrap and squeeze the zucchini to extract all their water. This is an important step to avoid soft/moist cookies. Set aside in a bowl.
In a large mixing bowl, beat egg with melted butter and erythritol.
Stir in grated zucchini, almond flour, baking powder, cinnamon, nutmeg, ginger, salt and vanilla,
Fold in sugar-free chocolate chips and chopped nuts and stir to combine
Scoop batter with an ice cream scoop maker and drop batter onto the prepared cookie tray leaving 1-inch (2 cm) space between each cookie. You should be able to make 20 small cookies (about 1 1/2 tablespoons batter per cookies) with this recipe and may need two cookie tray to lay all the cookies.
Press each cookie with your hands to flatten and smooth sides to create a lovely round cookie.
Bake one cookie tray at a time in your center rack oven, leaving the extra dough/cookie rack at room temperature to bake next.
Bake for 12-15 minutes or until slightly golden brown on the sides.
Cool 10 minutes on the rack, you can sprinkle extra sugar-free chocolate chips at this time, they will melt and add a lovely chocolate flavor.
Then slide a spatula under each cookie to transfer them, one by one, onto a cooling rack.
Cool 30 minutes on the rack before eating, they will firm up at room temperature and achieve their best texture after 2 hours.
Store in a cookie jar at room temperature up to 4 days or freeze for later in zip bags. Defrost 3 hours before on a rack, at room temperature.