In a large bowl, whisk together the flour, baking powder, kosher salt, and granulated sugar until well combined.
In a medium bowl, whisk together the buttermilk, orange juice, orange zest, egg, and melted butter until smooth.
Pour the wet ingredients into the dry ingredients and stir until just combined. Be careful not to overmix; a few lumps are fine. If the batter seems too thick, add a tablespoon or two of additional buttermilk to reach a pourable consistency.
Gently fold in chopped cranberries.
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. Spread the batter out more, if necessary, to about a 4-inch diameter.
Working in batches, being careful not to overcrowd the pan, cook the pancakes for 3-4 minutes, or until the bubbles begin popping on top and they are golden brown.
Gently, but quickly, flip over the pancakes. Cook an additional 3-4 minutes until the other side is also golden brown.
Before the next batch, wipe out the pan with a paper towel and repeat with the remaining pancake batter.
Serve warm, topped with cranberry maple syrup.