Gently wrap the grated zucchini in a paper towel or a clean towel and squeeze out any excess water. Discard the liquid and set the zucchini aside.
To a large bowl add the buttermilk, brown sugar, melted butter, vanilla, and the egg. Whisk to combine.
Gently fold in the grated zucchini and mix until incorporated.
In a separate medium bowl whisk together the flour, cinnamon, baking powder, baking soda, and salt.
Fold the flour mixture into the zucchini mixture and mix until just combined. Allow the batter to rest for 5-10 minutes while you prepare the skillet.
Spray a nonstick skillet or griddle with cooking spray and heat over medium heat, about 300°F.
When hot, pour ⅓ cup of batter into the skillet. If necessary, spread the batter out more, to about a 4-inch diameter.
Working in batches, being careful not to overcrowd the skillet or griddle, cook the pancakes for 3-4 minutes, or until the bubbles begin popping on top of the pancake and they are golden brown on the bottom.
Gently, but quickly, flip over the pancakes. Cook an additional 3-4 minutes until the other side is also golden brown.
Wipe out the pan with a paper towel, and repeat with the remaining pancake batter.
Serve warm, topped with maple syrup (or your favorite toppings).