Preheat oven to 350 degrees Fahrenheit. Prepare 12 cupcake pan with liners or grease.
Combine flour, baking powder, baking soda, salt, cinnamon, ginger powder, and nutmeg in a bowl and stir until incorporated. Set aside.
Combine zucchini, eggs, brown sugar, sour cream, butter, and vanilla extract in a large bowl. Stir until combined. The mixture will be wet.
Slowly add flour mixture to wet mixture. The mixture will be thick.
Add mixture into cupcake pan, about ⅓ cup of batter per cupcake. Sprinkle turbinado sugar over the cupcakes.
Bake in preheated oven for 23-25 minutes, or until muffins are golden and a toothpick entered in the center comes out clean.
Allow muffins to cool in the pan for about 5 minutes, then transfer to a cooling rack to complete cooling. Serve and enjoy :)