In a large bowl, whisk together flour, baking powder, cinnamon, and salt. In a medium bowl, whisk together milk, sweet potato, eggs, brown sugar, melted butter, and vanilla. Make a well in center of flour mixture; stir in milk mixture just until combined. Fold in pecans.
In a large cast-iron skillet or cast-iron griddle, heat 1 tablespoon oil over medium heat. Pour batter by ½ cupfuls onto pan, spreading slightly. Cook until edges are dry and bubbles form in center of pancakes, about 3 minutes; turn and cook until browned, 2 to 3 minutes more. Repeat with additional oil and batter. Serve with butter and syrup. Garnish with pecans, if desired.
Notes
For mashed sweet potato, bring 1 large sweet potato that’s been peeled and cubed and water to cover to boil in a small Dutch oven over high heat. Reduce heat, and simmer until tender, about 10 minutes. Drain well, and mash potato until smooth.
Recipe by Southern Cast Iron at https://southerncastiron.com/sweet-potato-pecan-pancakes/