In a large mixing bowl, whisk together the all-purpose flour, brown sugar, baking powder, baking soda, ground cinnamon, ginger, nutmeg, and sea salt until thoroughly combined and free of lumps.

In a separate medium bowl, whisk together the pumpkin puree, buttermilk, eggs, melted butter, and vanilla extract until completely smooth and velvety.

Pour the wet pumpkin mixture into the dry flour bowl. Using a silicone spatula, fold gently just until the flour is incorporated and no dry streaks remain. A few small lumps are completely fine and yield the fluffiest pancakes! Let batter rest for 5 minutes.

Preheat a cast-iron skillet or nonstick electric griddle to medium heat (around 350°F / 175°C). Lightly grease with butter or oil. Pour 1/3 cup of batter per pancake onto the griddle. Cook for 2 to 3 minutes until bubbles form across the surface and edges look set. Slide a thin spatula underneath, flip gently, and cook for another 1 to 2 minutes until golden-brown and cooked through.

In a small bowl, beat softened butter, maple syrup, and cinnamon with a hand whisk or fork for 1 minute until fluffy and spreadable. Stack warm pancakes high, top with a generous dollop of whipped maple butter, scatter with toasted pecans, and drizzle generously with warm maple syrup.