In a large bowl, whisk together flour and cinnamon. Make a well in center of mixture. In a medium bowl, stir together buttermilk, brown sugar, melted butter, vanilla, and eggs. Add to dry ingredients, stirring until just combined. Fold in banana.
In a large cast-iron griddle or skillet, heat 1 tablespoon oil over medium heat. Working in batches, drop batter by 1⁄3 cupfuls 1 inch apart over hot oil. Cook until edges are dry and bubbles form in center of pancakes, about 3 minutes; turn, and cook until browned, about 2 minutes more. Use remaining oil as needed. Serve with bananas and syrup.
Recipe by Southern Cast Iron at https://southerncastiron.com/banana-pancakes/