Grate the zucchini using the fine side of a box grater and squeeze out as much excess moisture as possible with a clean kitchen towel.
In a large bowl, whisk together the flour, sugar, baking powder, baking soda, salt, and cinnamon (if using).
In a separate bowl, whisk together the buttermilk, eggs, melted butter, and vanilla extract.
Pour the wet ingredients into the dry ingredients and stir gently until just combined. Do not overmix.
Fold the grated zucchini into the batter until evenly distributed.
Let the batter rest for 5 minutes to help create extra fluffy pancakes.
Heat a lightly greased nonstick skillet or griddle over medium heat.
Pour about ¼ cup of batter onto the skillet for each pancake.
Cook for 2–3 minutes, until bubbles appear on the surface and the edges begin to set.
Flip and cook for another 1–2 minutes, until golden brown and cooked through.
Serve warm with your favorite toppings.