I start by whisking the flour, brown sugar, baking powder, baking soda, salt, and all the spices together in a large bowl. This step spreads the leavening and spices evenly through the flour so you don't get a clump of cinnamon in one bite. It only takes a minute, but it makes a real difference in the final texture.
In a separate bowl, I whisk the buttermilk, pumpkin puree, egg, melted butter, and vanilla extract until smooth. The mixture should look like a thick, creamy orange batter with no streaks of egg or butter left. I like to let the melted butter cool slightly first so it doesn't scramble the egg when they combine.
I pour the wet ingredients into the bowl with the dry ingredients and stir gently with a spatula or whisk. I only mix until the flour disappears, since overmixing leads to tough, chewy pancakes instead of soft, fluffy ones. A few small lumps in the batter are completely fine and expected.
While the batter rests for a couple of minutes, I heat my griddle or skillet over medium-low heat and add a light coating of butter or oil. Getting the temperature right matters here, since too hot and the outside burns before the inside cooks through. I test it with a small drop of batter first to make sure it sizzles gently.
I scoop about a quarter cup of batter onto the griddle for each pancake, leaving space between them to spread. I wait until bubbles form across the surface and the edges look set before flipping, usually around two to three minutes per side. Each side should turn a deep golden brown with a slightly crisp edge.
Once both sides are cooked through, I transfer the pancakes to a plate and keep them warm under a clean kitchen towel while I finish the rest of the batch. Serving them warm right off the griddle is when they taste their absolute best.