In a medium bowl, whisk together instant oats, whole wheat or gluten-free flour, baking powder, ground cinnamon, ground nutmeg, and salt until evenly combined.

In a separate bowl, combine melted coconut oil or unsalted butter, egg, and vanilla extract. Whisk together until fully incorporated. Stir in pure maple syrup.

Pour the dry oat mixture into the wet ingredients, stirring until just incorporated. Fold in freshly grated zucchini.

Cover the bowl with plastic wrap or a lid and chill the cookie dough in the refrigerator for 30 minutes.

Preheat your oven to 325°F (160°C). Line a baking sheet with silicone baking mat or parchment paper.

Drop the chilled cookie dough into rounded scoops onto the prepared baking sheet. Flatten each scoop to about ⅜-inch thick.

Place the baking sheet in the preheated oven and bake for 11-14 minutes until lightly golden.

Remove the cookies from the oven and let them cool on the pan for 10 minutes before transferring to a wire rack.