In a medium bowl, use a fork to blend the dry ingredients together.
In a larger bowl, beat together the white sugar, brown sugar, eggs, vanilla extract, coconut oil, maple syrup, and grated zucchini using a mixer.
Gradually add the dry ingredients to the wet mixture until a smooth batter forms.
Spoon the batter into a greased and floured donut pan, filling each cavity about three-quarters full.
Bake in a preheated oven at 350°F for 10-12 minutes, or until a toothpick inserted into the thickest part comes out clean. Be careful not to overbake to avoid dryness.
Once baked, remove the donuts from the oven and transfer them to a cooling rack.
For the glaze topping, melt the white chocolate chips in a glass measuring cup in the microwave, using 30-second intervals and stirring between each until fully melted (approximately 1 minute). Stir in the maple syrup, then drizzle over each donut.
Add sprinkles immediately if desired, so they adhere to the glaze. For a thicker icing suitable for piping, use less maple syrup.