Grate the zucchini and squeeze out as much excess moisture as possible using a clean kitchen towel or paper towels.
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 in the grated zucchini and blueberries.
Heat a lightly greased nonstick skillet or griddle over medium heat.
Pour about ¼ cup of batter onto the hot skillet for each pancake.
Cook for 2–3 minutes, until bubbles form on the surface and the edges begin to set.
Flip carefully and cook for another 1–2 minutes, until golden brown and cooked through.
Repeat with the remaining batter and serve warm with your favorite toppings.