Preheat oven to 350 degrees F (175 degrees C). Grease a muffin tin or line with paper liners.
Whisk flour, brown sugar, pumpkin pie spice, baking soda, salt, and baking powder together in a large bowl.
Whisk coconut oil, eggs, and vanilla extract together in a separate bowl. Add to flour mixture; stir until just combined. Fold pumpkin puree and zucchini into the batter.
Scoop batter into the prepared muffin tin.
Bake in the preheated oven until a toothpick inserted into the center has a few moist crumbs attached, 18 to 24 minutes.
