Preheat the oven to 350 degrees. Generously grease a bundt pan with melted butter or cooking spray. Set aside.
Place the grated zucchini in a dish towel and squeeze to remove excess liquid and set aside.
Whisk together the flour, baking powder, baking soda, salt, and cinnamon in a small bowl. Set aside.
In a large bowl, whisk together the sugars, eggs, and coconut oil until frothy, about 1 minute. Stir in the vanilla. Add the dry ingredients to the wet ingredients, stirring just until combined. Stir in the zucchini, carrot, and coconut just until incorporated. Pour the batter into the prepared pan and bake on the center rack of the oven for 45-50 minutes, checking for doneness after 45 minutes. The cake is done when a toothpick inserted into the center comes out clean. Cool on a wire rack for 10 minutes, then carefully use a knife to loosen the cake from the pan and turn out onto the wire rack to continue cooling.
Prepare the glaze:
Beat the cream cheese in a medium bowl with a handheld mixer at medium speed until smooth. Add the powdered sugar and beat until incorporated. Add in the orange juice and zest, and beat until combined. If you'd like your glaze to be thinner, add a bit more orange juice.
Place the cooled cake on your serving plate and drizzle the glaze over it. Garnish with the toasted pistachios and coconut flakes, if using, and enjoy!
Notes
Total time above includes 30 minutes cooling time for the cake.
Leftover cake should be stored covered in the refrigerator.