Preheat your oven to 350°F and line a 12-cup muffin tin with muffin liners (or spray with nonstick cooking oil).  Melt the butter in a microwave-safe dish.

Shred the zucchini using a box grater until you have 1 cup, then squeeze out excess moisture using paper towels.  

In a medium-sized mixing bowl, whisk the flour, baking soda, salt, and cinnamon.

In a large mixing bowl, combine the melted butter, cane sugar, brown sugar, buttermilk, pumpkin purée, eggs, and vanilla extract.  Whisk until smooth.

Gently fold the shredded zucchini into the wet ingredients.

Gradually add the dry ingredients to the wet ingredients, mixing after each addition. Mix until no streaks remain. 

Using a large spoon, fill each muffin cup almost to the top with batter. 

Bake for 20-23 minutes, or until a toothpick inserted into the center of the muffins comes out clean. 

Let the muffins cool in the tin for a few minutes, then remove to a wire rack and cool completely. 

Enjoy!